Dissertations / Theses on the topic 'Ostriches'

DNA sequencing and restriction fragment length polymorphism analysis (RFLP) of polymerase chain reaction (PCR) amplified mitochondrial DNA fragments, and random amplified polymorphic DNA sequence (RAPD) analysis were techniques evaluated in this study for applicability in the investigation various aspects of genetic diversity within the ostrich (Struthio camelus). The genetic aspects that were investigated were (i) relationships between ostrich subspecies, (ii) genetic variability between and within domesticated populations of southern African ostriches (Struthio camelus australis), (iii) linking egg production in domesticated ostriches to RAPD profiles, and (iv) determining the zygosity of twin ostriches. In the first part of this study DNA sequencing and the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) methods were evaluated for resolving genetic differences in the small mtDNA fragments ofthe ostrich. DNA sequencing ofPCR amplified 450 bp 12S rRNA gene fragments of representatives from the southern African population ostrich (S.c. australis) did not reveal any differences between the populatiohs from different geographical areas, representing ostrich lineages with different breeding histories. The PCRRFLP analysis ofmtDNA fragments (450 bp 12S rRNA gene fragment and 550 bp D-loop region) also did not reveal any genetic variability between the domesticated s.,c. australis populations included in this study. PCR-RFLP analysis of a 450 bp 12S rRNA gene fragment, however, showed differences between the subspecies s.c. australis and s.c. molybdophanes. The proportion of shared fragments (F) between these two subspecies was 0.286 and nucleotide sequence divergence estimated at 8.9 %. Divergence time between these two subspecies was estimated at 4.5 million years ago. The data presented from this study are comparable to the data from a previous study in which the entire mitochondrial genome and a larger number of restriction enzymes were used. The PCR-RFLP method thus demonstrated its usefulness for genetic studies of ostriches at thesubspecies level. The sequences used in this study could not reveal any markers that were useful for genetic studies of ostriches at the population level. In the second part of the study the RAPD method was evaluated for application in the genetic studies of ostriches. RAPD profiles, based on three RAPD primers, revealed differences between three subspecies of ostriches and indicated relationships between these subspecies that are consistent with observations from other studies. The numerical analysis of pooled and individual primer data demonstrated that the subspecies s.c. australis is more closely related to s.c. massaicus than to s.c. molybdophanes. RAPD marker differences between s.c. molybdophanes on the one hand, and s.c. massaicus and s.c. australis on the other is also consistent with observations from studies that proposed separate specie~ status for s.c. molybdophanes. RAPD analysis by five primers revealed geographic variation between s.c. australis populations. The clustering patterns observed in the dendrograms and Neighbour Joining Trees generated by computer programs showed trends of separating ostric1;t populations into geographical groups, possibly reflecting their different breeding histories. In the RAPD profiles of the inbred population, band-sharing was generally greater than in the outbreeding group. RAPD analysis thus showed that it may be a useful method in the population studies of domesticated S. c. australis. RAPDs also generated data that grouped ostriches according to trends in egg production capabilities. Analysis ofRAPD profiles by computer software showed a Neighbour Joining Tree and a dendrogram that predominantly grouped ostriches into clusters associated with either good or poor egg production. Evidence supporting the suitability of RAPDs as a tool in breeding programmes of ostriches was thus provided by this study. RAPDs also provided data, demonstrating that two sets of ostrich twins were non-identical twins. It was demonstrated by this study that RAPDs analysis may be a useful technique for applying to (1) systematic (2) population (3) breeding and (4) twin studies of ostriches (Struthio camelus).

Human embryonic stem cell research would seem to offer the prospect of developing a greater understanding of, and potential therapies for, common degenerative diseases such as diabetes mellitus, Alzheimer’s and Parkinson’s disease. Despite the fact that some Irish institutions engage in such research, Ireland is one of the few countries in Europe which has failed to produce any relevant regulatory framework or legislation. This is largely because embryo research and its regulation remain mired in conflicting socio-political values and interests, despite the fact that the in vitro human embryo is not afforded any legal protection under the Irish Constitution. This thesis seeks to examine the current Irish legal lacuna in relation to embryos and embryonic stem cell research. The first of the three papers making up the core of this thesis reviews the background to the moral, legal and social factors that have contributed to the extant Irish position. A description of the divergent policies enacted in other jurisdictions is also given to outline possible policy options which may be considered by Ireland in the future. The views of relevant stakeholders on the impact of the regulatory lacuna are explored in the second paper through a series of semi-structured interviews. These interviews highlight a surprising level of consensus on the need for the Irish legislature to act and introduce regulations to provide certainty, in one way or the other, in this area of scientific innovation. A procedural mechanism is proposed in the third paper which could allow the development of policy and concomitant regulation in Ireland in this area. It is hoped that the procedural process and resultant framework would be sufficiently inclusive as to be acceptable to the majority of people in Irish society. In conclusion, it is argued that it is undesirable that a modern pluralist democracy (as Ireland aspires to be) should regard legislative inertia and non-regulation as the preferred method of dealing with morally challenging scientific endeavour. Instead, appropriate procedural mechanism should be utilised to allow for the development of apposite policies.

Thesis (MSc)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: When modern man assumed the responsibility of domesticating animals for his own purposes, he directly accepted the responsibility associated with feeding and caring for them. Considering intensive production systems, nutrition is one of the most important aspects in maintaining healthy livestock as well as ensuring profitability is achieved. This is due to the fact that the feeding of the livestock is often the most expensive overhead cost encountered. In ostrich production systems, nutrition costs total an estimated 70 – 80% of the costs associated with rearing the birds from chick to slaughter. When dissecting the typical composition of these ostrich diets, it becomes evident energy and protein are two of the most important, and abundant, nutrients found. Therefore, this study was conducted to investigate the effects of different concentrations of protein and energy in the diets of slaughter ostriches, on their production parameters. In the first study (Chapter 3), five diets with different protein concentrations were formulated across the four feeding phases of slaughter ostriches (pre-starter, starter, grower and finisher). Three replications per treatment were conducted resulting in 15 camps of ostriches. Significant differences (P < 0.05) were found in the live weights of the birds at the end of each feeding phase except the finisher phase. In terms of the production parameters, differences (P < 0.05) were found for the dry matter intake (DMI), average daily gain (ADG) and the feed conversion ratio (FCR). Results indicated that the birds on the middle diet (control) and on the diets containing proportionally higher protein concentrations, although not different from each other, consistently outperformed those on diets containing lower concentrations of protein. These trends were also evident when comparing the cold carcass and thigh weights of the treatment birds post-slaughter. Therefore, from a financial standpoint, it could be concluded that increasing the protein content of the diets beyond that level currently used in industry (control) is not sensible. The second study (Chapter 4) was an evaluation on the primary products harvested from the birds utilized in the first study, namely the feathers, skin and meat. The aim of the investigation was to determine if the dietary protein concentrations had any effect on these products. No differences (P > 0.05) were observed across the feather yields or classes measured, except for the ‘tail feathers’, where the birds fed the lowest protein levels in their diets yielded the fewest. Differences (P < 0.05) were however found in selected skin parameters measured. Decreased dietary protein resulted in smaller wet skin size, smaller sizes of the feather nodules, as well as smaller crust size after the tanning process was completed. However, this had no impact (P > 0.05) on the skin grades achieved. Hence it became clear that dietary protein has an impact on the skin size achieved, which did not translate into differences in skin quality. Similarly, it did not affect the feather yields or quality. Energy is the most important nutrient in livestock diets as it is the first limiting nutrient influencing intake. Therefore, in the third study (Chapter 5), treatments in the form of five different levels of energy in the diets of ostriches, were investigated. Structurally, the layout was similar to the first study with three replications per treatment yielding 15 camps of ostriches. Significant differences (P < 0.05) were found between the live weights of the birds after the pre-starter phase, but not overall after the completion of the trial. The middle diet (diet 3) containing 14.5 MJ ME/kg displayed the highest gains per day of 216.0 ± 8.08 g per chick. The results of the growth were mirrored in the production parameters (DMI, ADG, FCR), where no differences (P > 0.05) were found for the rest of the feeding phases. In a follow up investigation of the effects of dietary, this chapter focused on the impact these different energy levels (Chapter 5) had on the primary products harvested after slaughter (Chapter 6). In particular, the feather yield and quality, skin yield and selected quality parameters, as well as the chemical composition of the meat was studied. No differences were found (P > 0.05) across any of the feather yields or classes measured. Concerning the skin yields and quality, similar results were found with no differences (P > 0.05) between the crust sizes or grades. With regards to the proximate composition of the meat, no major effect (P > 0.05) was found as a result of the treatment diets. Therefore, dietary energy content exhibited little influence over the feather, skin and meat parameters measured in this study.
AFRIKAANSE OPSOMMING: Die oomblik toe die nuwerwetse mens die verantwoordelikheid aanvaar het vir die mak maak van diere vir sy eie gebruik, het hy direk die verantwoordelikheid aanvaar wat geassosieer word met hul voeding en versorging. Met inagneming van intensiewe produksiestelsels is voeding een van die belangrikste aspekte in die handhawing van gesonde vee asook om winsgewendheid te verseker. Dit is as gevolg van die feit dat die voeding van diere dikwels die grootste oorhoofse uitgawe is. In volstruisproduksiestelsels bereik die voedingskostes ‘n totale geskatte hoeveelheid van 70 – 80% van die kostes wat geassosieer word met die grootmaak van die voëls vanaf kuiken tot slagvoël. Wanneer die tipiese samestelling van hierdie volstruisdiëte ontleed word, is dit duidelik dat energie en proteïene twee van die mees belangrike en volopste voedingstowwe is wat gevind word. Hierdie studie was dus onderneem om die effek van verskillende konsentrasies proteïene en energie in die diëte van slagvoëls en hulle produksieparameters te ondersoek. Vir die eerste studie (Hoofstuk 3) is vyf diëte met verskillende proteïenkonsentrasies geformuleer vir die vier voedingsfases van slagvolstruise (voor-aanvangs, aanvangs, groei en afronding). Drie herhalings per behandeling is gebruik wat 15 volstruiskampe tot gevolg gehad het. Betekenisvolle verskille (P < 0.05) in die lewende gewig van die voëls is aan die einde van elke voedingsfase gevind, behalwe vir die afrondingsfase. In terme van die produksieparameters is verskille (P < 0.05) gevind vir die droë materiaalinname (DMI), gemiddelde daaglikse toename (GDT) en die voeromsetverhouding (VOV). Resultate het getoon dat voëls wat die middelste dieet (kontrole) en diëte wat proporsioneel hoër proteïenkonsentrasies bevat het, alhoewel hulle nie van mekaar verskil nie, konsekwent beter presteer het as die wat diëte met laer proteïenkonsentrasies ontvang het. Hierdie tendense is ook waargeneem toe die koue karkas- en dygewigte van die eksperimentele voëls na-doods vergelyk is. Vanuit ‘n finansiële oogpunt kan daar dus tot die gevolgtrekking gekom word dat dit nie sinvol sal wees om die proteïeninhoud van volstruisdiëte te verhoog bo die vlak wat tans in die industrie (kontrole) gebruik word nie. Tydens die tweede studie (Hoofstuk 4) is die primêre produkte (vere, velle en vleis) wat vanaf die volstruise in die eerste studie geoes is, geëvalueer. Die doel van hierdie studie was om te bepaal of die verskillende proteïenkonsentrasies in die dieet enige effek op hierdie produkte het. Geen verskille (P > 0.05) is by die veeropbrengste of die verskillende veertipes wat gemeet is, waargeneem nie, behalwe vir die stertvere, waar die voëls wat die laagste proteïenvlakke in hulle diëte ontvang het, die laagste opbrengs gelewer het. Verskille (P < 0.05) is egter gevind in die geselekteerde velparameters wat gemeet is. ‘n Vermindering in die proteïenkonsentrasie het ‘n kleiner nat velgrootte tot gevolg gehad, asook ‘n afname in knoppiegrootte nadat die looiproses voltooi is. Hierdie waarneming het egter geen invloed (P > 0.05) op die gradering van die velle gehad nie. Dit het dus duidelik na vore gekom dat die dieetproteïen wel die velgrootte wat bereik is, beïnvloed het, maar nie tot verskille in velkwaliteit gelei het nie. Veeropbrengs en –kwaliteit is ook nie deur die dieetproteïen beïnvloed nie. Energie is die eerste beperkende voedingskomponent wat voerinname bepaal. Gegewe die groot invloed wat dit op voerinname het, is dit dus die mees belangrike komponent in die dieet van vee. Vandaar dan die derde studie (Hoofstuk 5) waar die behandelings in die vorm van vyf verskillende energievlakke in die diëte van volstruise ondersoek is. Die struktuur en uitleg van die studie was soortgelyk aan die eerste studie met drie herhalings per behandeling wat 15 volstruiskampe tot gevolg gehad het. Betekenisvolle verskille (P < 0.05) is gevind tussen die lewende gewigte van die voëls na die voor-aanvangsfase, maar nie nadat die hele proefneming voltooi is nie. Die middelste dieet (dieet 3) wat 14.5 MJ ME/kg bevat het, het die hoogste toename per dag van 216.0 ± 8.08 g per kuiken opgelewer. Groeiresultate is weerspieël in die produksieparameters (DMI, GDT, VOV), waar geen verskille (P > 0.05) in die res van die voedingsfases gevind is nie. Tydens ‘n opvolgondersoek rakende die effek van dieet, het hierdie hoofstuk gefokus op die impak wat die verskillende energievlakke (Hoofstuk 5) op die primêre produkte wat na-doods geoes is. Daar is in besonder na die vere-opbrengs en –kwaliteit, velgrootte en geselekteerde kwaliteitparameters, asook die chemiese samestelling van die vleis gekyk. Geen verskille (P > 0.05) is by die veeropbrengste of die verskillende veertipes wat gemeet is, gevind nie. Met betrekking tot die velgroottes en -kwaliteit, is soortgelyke resultate gevind met geen verskille (P > 0.05) tussen die knoppiegrootte en –gradering nie. Met verwysing na die proksimale samestelling van die vleis is geen betekenisvolle effek (P > 0.05) as gevolg van die eksperimentele diëte waargeneem nie. Die inhoud van die dieetenergie het dus ‘n klein invloed op die vere-, vel- en vleisparameters wat in hierdie studie geëvalueer is, gehad.

Adequate and appropriate nutrition is essential for the production of high quality commercially farmed animal species. Although South Africa has had a well-established ostrich industry for over a century, little information on ostrich nutrition, in particular the specific nutritional requirements at different stages of production, is available. The industry has consequently relied heavily on data derived from poultry and pigs, but this has often proved to be unsatisfactory for ostriches and has resulted in serious nutritional-related problems. Recent studies on the metabolisable energy of specific components of diet formulations and balanced diets have indicated that ostriches have enhanced digestibility compared with poultry and pigs. At the same time, in the present economic climate, it is necessary to find cost-effective diets for breeding birds without compromising egg and chick production. This study primarily assessed the effect of different dietary protein and energy levels on production parameters and body condition of breeding female and male ostriches. The energy content of the diet appears to be the main constraint to egg production and breeders on low energy diets laid fewer eggs and lost more body condition compared with breeders fed higher energy diets. A diet with 8.5 MJ/kg DM and 10% protein with well balanced amino acids appears to be sufficient for female breeders without compromising production and a diet with 7.5 MJ/kg DM and 10% protein appears suitable for breeding male ostriches. Different dietary energy and protein levels similarly had little or no effect on egg quality and composition. This study also assessed the carry-over effect of the nutritional regime in one year on the production in the following breeding season. Females fed diets as low as 7.5 MJ/kg ME in the previous breeding season produced significantly fewer eggs in the next breeding season, which resulted in lower chick production. Energy had no effect on the percentage infertile eggs or on the initial egg weight. Different levels of dietary protein had no effect on egg production, egg weight, fertility, hatchability and initial chick weight.

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: This research study consists of three investigations with regard to ostrich (Struthio camelus var. domesticus) production, meat quality and the processing of ostrich meat into a value added meat product. The first study was conducted in order to establish whether the gradual replacement of soybean oilcake meal with cottonseed oilcake meal (CSOCM) as a protein source in the diet of slaughter ostriches would affect ostrich growth performance and meat quality. A total of 105 ostriches were divided into five feeding groups according to the CSOCM inclusion level: Control (0% CSOCM), 3%, 6%, 9% and 12% CSOCM, and fed with experimental diets from 6 to 13 months of age. As a result of feeding CSOCM, the final live weight and the average daily gain significantly increased in the 12% CSOCM group compared to the other treatment diets. The proximate composition, cholesterol content, mineral and fatty acid profile of the meat remained unaffected. Considering all the results, CSOCM may be used as an alternative protein source to soybean oilcake meal in ostrich nutrition, resulting in decreased feed costs. Secondly, a descriptive sensory analysis, together with chemical and physical measurements, was performed to determine whether the manipulation of the fatty acid composition in the fan fillet (Iliofibularis muscle) as a result of feeding CSOCM would be detected on a sensory level. Two levels of CSOCM were investigated; 0% as a control and 9% CSOCM. No significant differences were found for the physical measurements (cooking loss (%) and shear force) as well as for the pH and proximate composition of the raw fan fillet. The Control group presented a higher (P<0.05) mono-unsaturated fatty acid (MUFA) content in the cooked fan fillet whereas the 9% CSOCM group showed a favourable increased (P<0.05) poly-unsaturated fatty acid (PUFA) content when compared to the cooked Control samples. As a result, the poly-unsaturated:saturated fatty acid (PUFA:SFA) ratio in the 9% CSOCM group was also higher (P<0.05). No differences (P>0.05) were found between the treatments for the n-6:n-3 (omega 6 to omega 3) ratio. The 9% CSOCM group had a more intense beef aroma, had a higher level of initial and sustained juiciness as well as increased tenderness (P<0.05). Inclusion of 9% CSOCM resulted in a favourable cooked ostrich fan fillet. Finally, the effect of feeding CSOCM on a processed ostrich meat product was investigated. Fan fillet (Iliofibularis muscle) from 13 month old birds receiving no cottonseed oilcake meal (Control) or 9% cottonseed oilcake meal (9% CSOCM) was used. Olive oil was used as a replacement for pork fat, and warthog (Phacochoerus africanus) meat was used to replace commercial pork meat in the production of a semi dry sausage, cabanossi. Olive oil was included at three levels (0%, 1% and 2%). Six treatments were investigated: Control 0% olive oil, Control 1% olive oil, Control 2% olive oil, 9% CSOCM 1% olive oil, 9% CSOCM 2% olive oil en 9% CSOCM 2% olive oil. The Control and 9% CSOCM ostrich meat did not differ significantly in chemical composition nor fatty acid profile. After smoking and drying the fat content in the cabanossi containing 0%, 1% and 2% olive oil averaged 7.2%, 7.45% and 8.65% respectively. Processed meat products containing less than 10% fat are classified as a low-fat meat product. Olive oil is a mono-unsaturated vegetable oil containing mainly Oleic acid (C18:1n9c), and low quantities of saturated fatty acids and polyunsaturated fatty acids. Total mono unsaturated fatty acids in the cabanossi increased from 47.0% to 73.0% of total fat, whilst total saturated fatty acids and total polyunsaturated fatty acids decreased from 40.6% to 19.9% and 11.6% to 6.6% respectively as olive oil increased from 0% to 2%. The inclusion of olive oil at 2% resulted in cabanossi with increased (P<0.05) tenderness, juiciness and cured red meat colour, all factors that appeal greatly to the consumer. Overall flavour was not adversely affected by the inclusion of olive oil. This investigation indicated that the use of CSOCM had no negative effect on the production performance of ostriches whilst a 9% CSOCM inclusion level resulted in meat that was found to be favourable by a trained sensory panel. Furthermore, the use of CSOCM as a feed component also had no negative effect on a processed product (cabanossi) derived from the meat obtained from the birds fed this feed component. The CSOCM used in this investigation had low levels of gossypol (10 to 20ppm) and more research is required on the effect of the use of CSOCM with higher levels of gossypol on the production performance of ostriches.
AFRIKAANSE OPSOMMING: Die studie het bestaan uit drie ondersoeke met betrekking tot volstruis (Struthio camelus var. domesticus) -produksie, -vleiskwaliteit en die vervaardiging van waarde-toegevoegde geprosesseerde volstruis-vleisprodukte. Die doel van die eerste studie was om vas te stel of die geleidelike vervanging van sojaboonoliekoekmeel met katoensaad-oliekoekmeel (CSOCM) as ‘n proteïenbron in die voeding van volstruise, die groeipersentasie en vleiskwaliteit van die Iliofibiularis spier (fan fillet) sal affekteer. ‘n Totaal van 105 volstruise is verdeel in vyf voedingsgroepe volgens die katoensaad oliekoekmeel insluitingsvlak: Kontrole (0% CSOCM), 3%, 6%, 9% en 12% CSOCM. Die onderskeie voedingsgroepe was van ses tot 13 maande ouderdom op die eksperimentele voere geplaas. Die resultate het aangedui dat die voëls in die 12% CSOCM behandelingsgroep ‘n betekenisvolle (P<0.05) toename in finale lewende massa asook gemiddelde daaglikse toename gehad het. Die proksimale samestelling, cholesterol-inhoud, mineraal- en vetsuursamestelling van die vleis was nie geaffekteer deur die insluiting van CSOCM nie. Die CSOCM kan dus wel as ‘n alternatiewe proteïenbron in die voeding van volstruise gebruik word. Laasgenoemde bevinding kan ook lei tot verlaagde voerkostes, aangesien CSOCM heelwat goedkoper is as sojaboon-oliekoekmeel. Die tweede deel van die studie was van ‘n chemiese asook sensoriese aard. ‘n Beskrywende sensoriese analiese is uitgevoer om vas te stel of die manipulering van die vetsuursamestelling in die volstruis fan fillet as gevolg van die CSOCM sensories waargeneem kan word. Die chemiese en fisiese eienskappe van die vleis is ook ondersoek. Twee vlakke van CSOCM inhoud is ondersoek; 0% (as kontrole) en 9% CSOCM. Geen betekenisvolle verskille is gevind vir die fisiese vleiskwaliteit (kookverliespersentasie en taaiheid), asook vir die proksimale samestelling en pH van die fan fillet nie. Die gekookte fan fillet van die Kontrole behandeling het ‘n betekenisvolle (P<0.05) toename in mono-onversadigde vetsure (MUFA) getoon en die 9% CSOCM het ‘n voordelige toename in poli-onversadigde vetsuur-inhoud (PUFA) gehad. Die poli-onversadigde tot versadigde vetsuurverhouding (PUFA:SFA) was as ‘n gevolg ook betekenisvol hoër. Geen verskille (P>0.05) is opgemerk in die omega-6 tot omega-3 poli-onversadigde vetsuurverhouding (n-6:n-3) nie. Met betrekking tot die sensoriese eienskappe het die 9% CSOCM ‘n meer opvallende beesvleis aroma, hoër vlakke van aanvanklike sappigheid en ook sagter vleis in vergelyking met die kontrole behandeling gehad (P<0.05). Insluiting van 9% CSOCM het gelei tot ‘n gekookte volstruis fan fillet van voornemende kwaliteit. Laastens is daar ondersoek ingestel op die vervanging van varkvet met olyfolie in die vervaardiging van ‘n volstruis cabanossi. Chemiese asook sensoriese analises is uitgevoer op die gedroogde en gerookte volstruis cabanossi. Vir die vervaardiging van laasgenoemde produkte is die fan fillet van 13 maande oue voëls van die Kontrole (0% CSOCM) en 9% CSOCM behandelings gebruik. Addisioneel tot die volstruisvleis is daar ook vlakvarkvleis (Phacochoerus africanus) gebruik om die kommersiële varkvleis te vervang. Olyfolie was ingesluit teen drie vlakke (0%, 1% en 2% van die totale mengsel). Ses behandelings was ondersoek: Kontrole 0% olyfolie, Kontrole 1% olyfolie, Kontrole 2% olyfolie, 9% CSOCM 1% olyfolie, 9% CSOCM 2% olyfolie en 9% CSOCM 2% olyfolie. Daar was geen verskille (P>0.05) in die chemiese en vetsuursamestellings van die Kontrole en 9% CSOCM volstruisvleis nie. Na die droging en rooksiklus was die gemiddelde vet-inhoud van die 0%, 1% en 2% olyfolie cabanossi monsters onderskeidelik 7.2%, 7.45% en 8.65%. Geprosesseerde vleisprodukte met ‘n vet-inhoud van minder as 10% word in die kommersiële vleisindustrie na lae vet vleisprodukte verwys. Olyfolie is baie ryk aan MUFA, veral Oleïensuur (C18:1n9c) en dit bevat ook lae hoeveelhede SFA en PUFA. Die totale MUFA inhoud in die cabanossi het toegeneem van 47.0% tot 73.0% terwyl die totale SFA en PUFA onderskeidelik afgeneem het van 40.6% tot 19.9% en 11.6% tot 6.6%, met ‘n olyfolie toename van 0% tot 2%. Die insluiting van olyfolie teen 2% het gelei tot ‘n sagter cabanossi wat meer sappig was met ‘n meer opvallende rooi gekuurde vleiskleur, wat almal eienskappe is wat dié produk meer aantreklik maak vir die verbruiker. Hierdie studie het aangedui dat CSOCM geen negatiewe effek gehad het op die produksie van volstruise nie. Volstruisvleis van die behandelingsgroep wat CSOCM teen 9% van die dieet ontvang het, het wel vleis geproduseer wat as aanvaarbaar aanskou was deur ‘n opgeleide sensoriese paneel. Die gebruik van CSOCM as ‘n voerbestandeel het ook geen negatiewe effek gehad op ‘n geprosesseerde produk (cabanossi) gemaak van die volstruisvleis nie. Die CSOCM wat in die huidige studie gebruik is, het baie lae vlakke van gossypol (10 – 20dpm) gehad en verdere ondersoek is noodsaaklik om die effek van CSOCM met hoër vlakke van gossypol op die produksie van volstruise te bevestig.

Hierdie verhandeling is ‘n samestelling van verskeie studies, elk opgeskryf in die formaat en styl soos vereis deur die Suid-Afrikaanse Vereeniging vir Diereproduksie (South African Society of Animal Science). Hoofstuk 1 is ‘n literatuurstudie bestaande uit ‘n algemene inleiding wat agtergrond oor die studie verskaf en sluit die probleemstelling in, naamlik die swak oorlewing van volstruiskuikens wat onder kunsmatige toestande grootgemaak word. Hoofstukke 2, 3, 4 en 5 bestaan uit die eerste vier studies, waartydens sekere bestuurs-aspekte, wat moontlik oorlewing van volstruiskuikens kan verbeter (nl: populasiedigtheid, tipe vloer-oppervlak, die aanwending van broeipare en die aanwending van peetouers), ondersoek is. Hoofstukke 6, 7, 8 & 9 handel oor studies wat gerig is om voeding meer aanloklik te maak vir volstruiskuikens teneinde voedselinname te stimuleer en sodoende produksie en oorlewing te verbeter (nl: verskaffing van groenvoer, geur van voer, kleur van voer en beligting van voer). Die laaste hoofstuk bestaan uit ‘n algemene gevolgtrekking en aanbevelings. Alhoewel daar gepoog is om herhaling in hoofstukke te beperk, was dit onmoontlik om herhaling van sekere gedeeltes van hoofstukke te voorkom.

Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The first study (Chapter 3) evaluated the growth response of ostrich chicks on diets containing three different levels of protein and amino acids. Linear and nonlinear models were fitted to the data and compared by using Akaike’s information criterion (AIC). The linear polynomial of the third degree had the lowest AIC value for all three treatments thus making it the most suitable model for the data. Significant differences were found between treatments for growth data. The results from this study can aid in describing the growth of ostriches subjected to assumed optimum feeding conditions. In the second study (Chapter 4), a range of diets was formulated for the five growth stages of ostriches (pre-starter, starter, grower, finisher and maintenance) according to their nutrient requirements. The diets were diluted with wheat straw. Three dilution levels (0%, 10% and 20%) were used for the pre-starter and starter phases, five dilution levels (0%, 15%, 30%, 45% and 60%) were used for the grower and the finisher phases, and five dilution levels (0%, 20%, 40%, 60% and 80%) were used for the maintenance phase. Weekly intake data were collected throughout each phase. Feed bulk restricted intake by 21% and 52% at the 10% and 20% dilution level, respectively (P < 0.05) in the pre-starter phase, whereas intake was not restricted during the starter phase(P > 0.05). Intake was constrained by 39% and 42% at the 45% and 60% dilution levels in the grower phase, respectively (P < 0.05), and by 17% and 39% at the 45% and 60% dilution levels (P < 0.05) in the finisher phase, respectively. Feed bulk restricted intake by 60% and 69% for the 60% and 80% dilution levels (P < 0.05), respectively, in the maintenance phase. Defining the bulk density that will constrain feed intake, as established in this study, will aid in least-cost feed formulations, feed intake modelling and growth predictions. In the third study (Chapter 5) the effect of three different dietary protein (with a specific associated amino acid content) concentrations on certain production parameters in growing ostriches were investigated. Significant differences were found for the final live weight of birds, cold carcass weight, thigh weight as well as for most of the weighed muscles at slaughter (350 days old). Concerning the growth and feed related parameters, only average daily gain (ADG) was influenced by dietary treatment (P < 0.05). Results indicated that birds on the diet with the medium protein performed optimally. One exception is the starter phase (26 – 47 kg) where chicks on the high protein diet outperformed those on the medium protein diet. In the fourth study (Chapter 6) the effects of different dietary energy concentrations on ostrich production parameters were examined in two different trials. The first trial included measurements from the pre-starter phase through the starter phase until the grower phase. The second trial was based on the finisher phase per se. Overall dietary levels provided in the pre-starter, starter and grower phases indicated better growth, FCR, skin size and grade, thigh weight, live weight, and carcass weight for the birds fed the medium energy diet. Dietary energy levels provided during the finisher phase indicated that the energy level above the medium level used improved growth rate and tanned skin size. The gender of the birds influenced carcass weight, growth rate, and certain feather parameters (P < 0.05). In the fifth study (Chapter 7) the effect of feather clipping at six to eight months of age on the production parameters of ostrich chicks were investigated. The study was conducted in three different trials. In each of the trials the feathers of half the amount of birds were clipped at six to eight months of age. Significant differences (P < 0.05) were found for the feed conversion ratio (FCR), the average daily gain (ADG) and for the quantity of valuable feathers. Results indicated that the growth rate and FCR was better for the birds which had their feathers clipped at six to eight months of age. Results also showed that the quantity of feathers with commercial value were significantly higher for the clipped group. This study showed that there may be an advantage for ostrich producers concerning the harvesting of feathers at six to eight months of age. The work in this thesis is a follow up on the framework set by Kritzinger (2011) and is part of the same project. Most of the results obtained in these studies will be incorporated in to the mathematical optimisation model of Gous and Brand (2008) for more accurate predictions concerning feed intake and other production parameters that may lower feeding costs.
AFRIKAANSE OPSOMMING: Die eerste studie (Hoofstuk 3) evalueer die groei van volstruiskuikens op diëte met drie verskillende vlakke van proteïene en aminosure. Liniêre en nie-liniêre regressiemodelle is op die data gepas en met Akaike se inligting kriterium (AIC) vergelyk. Die liniêre polinoom van die derde graad het die laagste AIC waarde vir al drie behandelings gehad. Daarom is die voorspellings van hierdie model gebruik om die groeidata te interpreteer. Beduidende verskille tussen behandelings vir groeidata (P < 0.05) is gevind. Die resultate van hierdie studie kan help met die beskrywing van die groei van volstruise, onderworpe aan aangeneemde optimale voedingsbehoeftes. In die tweede studie (Hoofstuk 4) is 'n verskeidenheid diëte geformuleer vir die vyf groeistadiums van volstruise (voor-aanvangs, aanvangs, groei, afronding en onderhoud) volgens hul voedingsbehoeftes. Die diëte is verdun met koringstrooi. Drie verdunningsvlakke (0%, 10% en 20%) is gebruik vir die voor-aanvangs- en aanvangsfase, vyf verdunningvlakke (0%, 15%, 30%, 45% en 60%) is gebruik vir die groei- en die afrondingsfase en vyf verdunningsvlakke (0%, 20%, 40%, 60% en 80%) is gebruik vir die onderhoudsfase. Weeklikse inname-data is ingesamel gedurende elke fase. In die voor-aanvangsfase het voerlywigheid (verhoging van ruvesel) inname beperk met 21% en 52% vir die 10% en 20% verdunningsvlakke (P < 0.05) onderskeidelik, terwyl inname nie beperk is gedurende die aanvangsfase nie (P > 0.05). Inname is beperk met 39% en 42% op die 45% en 60% verdunningsvlakke in die groeifase (P < 0.05) onderskeidelik, en met 17% en 39% op die 45% en 60% verdunningsvlakke in die afrondingsfase (P < 0.05), onderskeidelik. Voerdigtheid het inname beperk met 60% en 69% vir die 60% en 80% verdunningsvlakke, onderskeidelik, in die onderhoudsfase (P < 0.05). Die definiëring van die digtheid of ruvoerinhoud van voer wat inname beperk, soos in die studie bepaal, sal help met die optimering van voerformulasies, voerinname-modellering en groeivoorspellings. In die derde studie (Hoofstuk 5) is die effek van drie verskillende dieëtproteïenkonsentrasies (met 'n spesifieke gepaardgaande aminosuurinhoud) op sekere produksieparameters in die groei van volstruise ondersoek. Beduidende verskille is gevind vir die finale lewende gewig, koue karkasmassa, boudgewig sowel as vir die meeste van die geweegde spiere van voëls op slagouderdom (350 dae oud). Met betrekking tot die groei en voedingsverwante parameters, is slegs die gemiddelde daaglikse toename (GDT) beïnvloed deur die dieet (P < 0.05). Resultate het aangedui dat voëls op die medium-proteïendieet optimaal presteer. Een uitsondering is die aanvangsfase (26 – 47 kg), waar kuikens op die hoë-proteïendieet beter gevaar het as die voëls wat die medium-proteïendieet ontvang het. In die vierde studie (Hoofstuk 6) is die invloed van verskillende dieet-energiekonsentrasies op volstruis-produksieparameters in twee verskillende proewe ondersoek. Die eerste proef het gestrek vanaf die voor-aanvangsfase, deur die aanvangsfase tot en met die einde van die groeifase. Die tweede proef is gedoen vir die afrondingsfase. In die voor-aanvangs-, aanvangs- en groeifase is beter groei, voeromsetverhouding (VOV), velgrootte en -graad, boudgewig, lewende gewig en karkasgewig verkry vir die voëls wat die standaard-energie dieet ontvang het (P < 0.05). Dieet-energievlakke wat tydens die afrondingsfase fase verskaf is, het aangedui dat die energievlak bo die medium-vlak verbeterde groeitempo en gelooide velgrootte tot gevolg het (P < 0.05). Die geslag van die voëls het ’n invloed gehad op karkasgewig, groei, en sekere veerparameters. In die vyfde studie (Hoofstuk 7) is die effek van die knip van vere, op die ouderdom van ses tot agt maande, op die produksieparameters van volstruiskuikens ondersoek. Die studie is uitgevoer in drie verskillende proewe. In elk van die proewe is die vere van die helfte van die hoeveelheid voëls geknip op ses tot agt maande ouderdom. Beduidende verskille is gevind vir die VOV, die gemiddelde daaglikse toename (GDT) en vir die hoeveelheid waardevolle vere (P < 0.05). Die groeitempo en VOV was beter vir die voëls waarvan die vere op ses tot agt maande ouderdom geknip is (P < 0.05). Resultate het ook getoon dat die hoeveelheid waardevolle vere aansienlik hoër was vir die groep waarvan die vere op ses tot agt maande ouderdom geknip is (P < 0.05). Hierdie studie het getoon dat daar 'n voordeel mag wees vir volstruisprodusente indien vere geknip word op die ouderdom van ses tot agt maande. Die werk in hierdie tesis volg op die raamwerk van Kritzinger (2011) en was deel van dieselfde projek. Die meeste van die resultate wat verkry is in die studies sal in die wiskundige optimeringsmodel van Gous en Brand (2008) geïnkorporeer word vir meer akkurate voorspellings van voerinname en produksieparameters wat die voerkostes kan verlaag.

Thesis (PhD (Botany and Zoology))—University of Stellenbosch, 2009.
Females of many bird species prefer to mate with males exhibiting elaborate ornamentation, which serves as an indicator of male quality. Such ornaments, called secondary sexual traits, could act as signals to females that males could confer direct and/or indirect genetic benefits (when offspring inherit superior genes), on offspring. In particular, it has been suggested that these signals relate to male ability to resist infections, as only high quality individuals are able to invest both in high immune defence and elaborate ornament expression. The ostrich (Struthio camelus) is the largest living bird and is a member of the family of flightless birds, the ratites. They are sexually dimorphic, males displaying black plumage, and a pink-coloured neck and bill; whereas females display dull-brown plumage (both sexes have white feathers). Little is known about the mating system of ostriches: they are promiscuous and in the wild, males and females have multiple partners. The communal nesting system of ostriches is unique in that only the major female and major male provide parental care, in the form of incubation and guarding the offspring until independence. Furthermore, a remarkable feature of cohorts is that offspring may differ greatly in size, and these size differences are likely to have a genetic basis arising from differing parental genotypic differences. As a trade-off between immune response and life-history traits has been documented in various bird species, I examined the relationships between male secondary sexual traits (and specifically colouration) and maternal investment; levels of immunocompetence in both parents and chicks; and chick growth. This study showed that females invest more at the egg stage in response to traits involved in the male courtship display: the colour of the neck, white and black body feathers, and the brightness of black feathers. As these traits, which are exposed during the courtship display as well as during male-male interactions, were related to male immune responses, I suggest that only high quality males will be able to display their condition optimally. Chicks with higher growth rates were found to have intermediate responses to stimulation of their humoral immune system with diphtheria and tetanus vaccines, suggesting that not only fitness benefits, but also costs are associated with mounting an immune response; and that variation in humoral responses and growth rates relates to how individuals trade off these costs and benefits. In addition, chick humoral responses were found to be related to the humoral response of both parents, but through different antibody responses (maternal responses to tetanus and paternal responses to diphtheria), suggesting that this component of the immune system is heritable. As the colouration of white feathers predicted chick growth rates, as well as a male’s ability to raise an antibody response, I suggest that this visual cue could serve as a signal to females of male humoral immunocompetence, therefore forming the basis of mate choice whereby females could increase the fitness of their offspring through higher growth rates.

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Although transport and lairage of ostriches are accepted causes of production losses, these losses have not yet been quantified. Transport and lairage regulations focus on the wellbeing of the birds and, by default reduce some losses. This thesis investigated weight losses and meat quality of ostriches as a result of transport density, lairage duration and lairage feed availability (ad libitum). All birds were reared on the same farm and loaded and transported together. They were randomly divided into their respective groups on loading for the transport trial, and on offloading for the lairage trial. Bird grouping was according to density for the transport trial (4 groups, H1, H2: 0.56m2/bird and L1, L2: 0.96m2/bird) and according to time spent in lairage and feed availability for the lairage trial (n=30 birds/group; L0hr and L24hr; n=15 birds/group L48hr and L48hr ad libitum feed). Behavioural observations of the ostriches showed a tendency of the ostriches to lean against objects and to orientate towards forces exerted on it to help keep its balance. Reactions to sound fluctuations were noted, with birds reacting towards changes in sound volume during transport and lairage. Timepoint numbers were allocated for each time the birds were weighed during the trial. Time points 1, 2, 3, 4 and 5 were allocated to loading, arrival, 19 hr in lairage, 31 hr in lairage and 39 hr in lairage respectively for Trial 2. Results showed no differences (P > 0.05) in live weights or meat quality parameters between Groups H1, H2, L1 and L2 during transport. Differences (P < 0.05) were found in cumulative weight losses between L0hr and the rest of the groups for time point 1. Differences between L48hr and L48hr ad libitum were found for time point 4 for cumulative weight loss. L48hr also differed significantly between the other lairage duration groups for dressing percentages as a function of loading weight. Ad libitum feed availability had a significant effect on live body weight changes but not the meat quality parameters for the groups held for 48hr in lairage. The number of birds having bruises (≈50% per group) was similar between groups and lairage had no influence on bruising. Results seem to indicate that the evaluated transport densities had no effect on the weight loss or meat quality of ostriches. However, the results indicate that the lairage period should be studied further with specific reference to weight losses during lairage. Meat quality was unaffected by the lairage parameters reported in this thesis.
AFRIKAASE OPSOMMING: Hoewel vervoer en voorslag hou (“lairage”) aanvaar word as die oorsake van produksieverliese, is hierdie aspekte nog nie gekwantifiseer nie. Regulasies in terme van vervoer en voorslag hou fokus op die welstand van die voëls en gevolglik verminder sommige verliese met hierdie faktore. Konflik tussen boere en sekondêre produsente (abattoirs en verwerkers) oor die kostes verbonde aan hierdie gewigsverliese, is in wese ‘n oorsaak van oorbruggingsfases (vervoer). Daarom is die voorslag hou-parameters van tyd, voerbeskikbaarheid en laai digtheid ondersoek. Twee proewe is geloods; een vir vervoer en een vir voorslag aanhou. Voëls is voor hulle op vragmotors gelaai is, geweeg en op spesifieke tye daarna geweeg. Diere van die laaidigtheidsproef is ingedeel in vier groepe (H1, H2: 0.56m2/voel en L1, L2: 0.96m2/voel). Met aflaai is die eerste toets groep geslag terwyl die tweede toets groep ingedeel is volgens die tyd gespandeer en voer beskikbaarheid in voorslag aanhou (n=30 voëls/groep - Groepe L0u, L24u; n=15 voëls/groep - L48u en L48u ad libitum gevoer). Gedrag van voëls is aangeteken tydens vervoer. Finale gewig was slagpale gewig en elke tyd periode waar die voëls geweeg is, is aangeteken as ‘n tydpunt. Vleiskwaliteit analises is gedoen op die linker boud se fan filet. ‘n Standaard rak leeftyd toets is ook gedoen om kwaliteit parameters te toets oor tyd. pH is gekatorigiseer volgens groepe om moontlike verskille te beklemtoon. Gedrag is opgeteken volgens die oriëntasie en steunings gewoontes van die volstruise gedurende vervoer. Voëls probeer hulle balans te hou deur op voorwerpe en op mekaar te leun, asook om hul liggaam oriëntasie te gebruik. Reaksies tot klank veranderinge is ook opgemerk tydens vervoer en voorslag aanhou. Resultate toon geen betekenisvolle verkille tussen digtheid groepe H1, H2, L1 en L2 nie. Geen gewigsverskille is gevind tussen vervoerdigtheid groepe nie. Vleiskwaliteit-parameters is ook ondersoek en geen verskille is gevind tussen groepe nie. Resultate toon wel betekenisvolle verskille in gewigsverlies-persentasie tussen groepe vir tyd in voorslag aanhou. Groepe L48u en L48u ad libitum, het onder andere betekenisvol verskille getoon vir tydpunt 4. Betekenisvolle verskille in uitslagpersentasie as funksie van begin-gewig tussen 48 uur en die res van die groepe is ook gevind. Verdere vleiskwaliteit-parameters (drupverlies, pH, ens.) tussen groepe het geen betekenisvolle verskille getoon nie. Resultate dui aan dat voer beskikbaarheid het ‘n invloed op gewigsverskille in voorslag aanhou. Regulasies vir voorslag hou, vervoer en welstand van volstruise sal moontlik verder ondersoek moet word met spesiale klem op die nut van voorslag aanhou en die se invloed op gewigsverlies. Vleiskwaliteits-parameters is nie beïnvloed deur die aspekte ondersoek nie.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The nutrient requirements for breeding ostriches are currently not well-defined. Quantification of the nutrient requirements will improve the financial wellbeing of the industry. A study of the growth of the reproductive organs and liver, together with various production studies, were therefore undertaken in order to gain knowledge about the nutrition of breeding ostriches, thereby quantifying the nutrient requirements of breeding ostriches. Various studies were conducted to determine the influence of dietary protein, amino acids and energy on production levels of breeding ostriches. In a first study, five diets, varying in crude protein (CP) but with a constant energy content of 9.2 MJ ME/kg feed, were provided at a feed intake level of 2.5 kg/bird/day. The dietary CP levels were 7.5%, 9.1%, 10.8%, 12.3% and 14.0%. No differences (P>0.05) between treatments (total eggs per female per season) were found for number of unfertilized eggs (eggs per female per season; 8.9±0.8), dead-in-shell chicks (8.0±0.5), number of chicks hatched (19.1±1.1) and change in mass of females (-16.2±1.6kg). A tendency was observed for a difference in total egg production (mean and standard error; 39.1±3.6; P=0.08). The 12.3% CP diet caused the lowest (P<0.05) change in live mass (-3.8±2kg) for male birds. No interaction (P>0.05) occurred between the genotype of the bird and the dietary protein concentration for both egg and chick production. In a second study, six diets varying in ME (MJ ME/kg feed), were provided at an average feed intake level of 3.4 kg/bird/day. The levels were 7.5, 8.0, 8.5, 9.0, 9.5 and 10.0 MJ ME/kg feed respectively. No differences (P>0.05) were observed for total eggs produced per female per season (44.8±7.8), number of chicks hatched (15.4±4.1), number of infertile eggs (11.5±3.8), number of dead-in-shell eggs (12.1±3.2) and change in mass of females (10.7±3.6kg). Males increased linearly (y=2.4x + 2.45; R2=0.09; P<0.05) in live mass as the dietary energy content increased. Two eggs per diet per month were analyzed for crude protein, crude fat and trace elements, and one egg per diet per month was analyzed for fatty acid composition. Eggs from the first and last month of the season were subjected to amino acid analysis. Analysis of variance showed no difference in crude protein and fat (P>0.05) content of eggs between the experimental diets, as well as for the calcium content of eggshells. The proline content differed (P<0.05) between the diets. The C18:3n-3 (linoleic acid) content of the eggs increased (P<0.05) amongst the dietary treatments. Crude protein, fat and C18:3n-3 content in eggs increased (P<0.05) for the number of the egg in the laying cycle. In a third study, the feed intake of breeding ostriches, as affected by dietary energy content was investigated. Average feed intake (kg feed/bird/day) was not affected (P>0.05) at any dietary energy level when levels of 8.0, 8.7, 9.4, 10.1, 10.8 and 11.5 MJ ME/kg feed were provided. The mean and standard error was 3.7±0.2kg. The production of breeding female ostriches was not influenced by dietary ME and protein at these feed intake levels. Ostrich birds do not have the ability to regulate their feed intake at any dietary energy level as used in this study. The amount of nutrients deposited in the eggs had no influence on the reproductive efficiency of the breeding female ostrich. The experiments also revealed that female breeding ostriches were independent of dietary energy and protein as used in this study for the mean frequency of egg laying at various dietary protein and energy levels (P>0.05). In a fourth study, the growth and development of the reproductive organs of female birds at the onset of the breeding season were investigated. The amount of nutrients needs to be determined in order to support the growth of the reproductive organs during the breeding season, due to the fact that these organs are linked to egg production. It was thus necessary to investigate whether the reproductive organs grew and developed during a season. The first slaughter interval was conducted at the start of the breeding season. The ovary, oviduct and liver were collected, weighed after each slaughter and analyzed. Ovary and oviduct were analyzed for crude protein and fat. No differences (P>0.05) were observed between the different slaughter intervals for the mass, crude protein and fat content of both organs. No trend (P>0.05) in the weight of the oviduct could be observed over the 49-day period, this weight being highly correlated with body weight; whereas the ovary weight tended to be correlated with the time after the onset of the breeding period, although the variation in weights, both within and between weighings, was very high. The variation in the weight of the ovary probably reflects differences in the laying pattern of individuals. The number of follicles were not affected (P>0.05) by the number of days after mating. Livers were assessed for crude protein and fat, but no difference (P>0.05) was detected between the intervals, but the weight difference amongst the slaughter intervals was significant (P<0.05), suggesting that the ostriches used liver reserves to supplement nutrients that obtained from the diet for the development of the reproductive organs. This data will be used in an optimising model (Brand & Gous, 2006) to predict the nutrient requirements of female breeding ostriches. This study suggests that the female breeding ostrich might need additional protein during the first 7 weeks of the breeding season. Results from Chapter 4 and previous studies were used to calculate the energy, protein and amino acid requirements for the egg production and maintenance of the breeding female ostrich. Two methods were used to determine the energy requirement for egg production. The Metabolisable Energy requirement for egg production (MEe) and efficiency of ME utilization for energy deposition in the egg (ko) was calculated as 12.2 MJ (for an average size egg of 1.4kg) and 0.8 respectively. The Effective Energy requirement for egg production (EEe) and maintenance (EEm) was calculated as 15.9 MJ/day and 17.1 MJ/day respectively. Average total daily protein requirement (TPt) was calculated as 175g day. The amino acid requirements for maintenance and egg production is also provided, which is lower than previous studies. This study also provides evidence that the nutrient requirements are different for every month of the breeding season.
AFRIKAANSE OPSOMMING: Tans heers daar onsekerheid oor die voedingsbehoeftes van volstruis broeivolstruise. Kwantifisering van die voedingsbehoeftes sal ‘n finansiële hupstoot aan die industrie gee. ‘n Groeistudie van die reproduksie-organe en lewer, tesame met ‘n aantal produksie-studies, is uitgevoer om inligting oor die voedingsbehoeftes van volstruis broeivoëls te versamel. Daarby is die voedingsbehoeftes teoreties bereken. ‘n Aantal studies was uitgevoer om die invloed van dieët proteïen en aminosure en energie op produksie-data te bepaal. Eerstens is vyf diëte, wisselend in ru-proteïen (RP) en beperk tot ‘n inname van 2.5 kg/voël/dag, aan broeivolstruise gevoer. Die RP van elke dieët was 7.5%, 9.1%, 10.8%, 12.3% en 14.0%. Die energiewaarde van die voer is konstant by 9.2 MJ ME/kg voer gehou. Geen verskille (P>0.05) was tussen die behandelings waargeneem vir aantal geil eiers (totale eiers geproduseer per voël per seisoen; 8.9±0.8), aantal dood-in-dop (8.0±0.5), aantal kuikens (19.1±1.1) en verandering in massa van wyfies (-16.2±1.6kg) nie. ‘n Neiging (P=0.08) is wel waargeneem vir totale aantal eiers geproduseer. Die gemiddelde en standaard fout was 39.1±3.6. Die 12.3% dieët het tot die laagste verandering (P<0.05) in lewendige massa (-3.8±2kg) vir die mannetjies gelei. Geen interaksie (P>0.05) was tussen die genotipe en dieët proteïen konsentrasie vir beide eier- en kuikenproduksie opgemerk nie. In ‘n tweede studie is ses diëte, variërend in ME (MJ ME/kg voer), by ‘n gemiddelde tempo van 3.4 kg/voël/dag gevoer. Die verskillende ME-vlakke was 7.5, 8.0, 8.5, 9.0, 9.5 en 10.0 MJ ME/kg voer. Geen betekenisvolle verskille (P>0.05) is vir totale eiers geproduseer per voël per seisoen (44.8±7.8), aantal kuikens uitgebroei (15.4±4.1), aantal geil eiers (11.5±3.8), aantal dood-in-dop eiers (12.1±3.2) en massa verandering van wyfies (10.7±3.6kg) opgemerk nie. Die mannetjies het toegeneem in liggaamsmassa (P<0.05) soos daar ‘n toename was in die energievlak van die dieët. Twee eiers per dieët per maand is vir ru-proteïen, vet en spoorelemente, en een eier per diet per maand vir vetsure ontleed. Eiers van die eerste en laaste maand van die seisoen is ontleed vir aminosure. Analise van variansie het aangetoon dat daar geen verskille (P>0.05) bestaan vir die ru-proteïen en vetinhoud van die eiers by die verskillende eksperimentele diëte, asook die kalsiuminhoud van die eierdoppe. Prolien vlakke het tussen die diëte verskil (P<0.05). Die C18:3n-3 (linoleïensuur) inhoud van die eiers het verskil (P<0.05) tussen die dieët behandelilngs. Vir die hoeveelste eier in die lê siklus het die ru-proteïen-, vet- en C18:3n-3 inhoud van die eiers verhoog (P<0.05). In ‘n derde studie is ondersoek ingestel na die voerinname van die broeivolstruise soos moontlik beïnvloed deur die energievlak van die dieët. Gemiddelde voerinname (kg voer/voël/dag) is nie (P>0.05) deur die verskillende dieët energie vlakke van 8.0, 8.7, 9.4, 10.1, 10.8 en 11.5 MJ ME/kg voer beïnvloed nie. Die gemiddelde en standaardfout was 3.7±0.2kg. Die produksie van broeivolstruise nie deur verskillende dieëtvlakke van proteïen en energie by vlakke soos gevoer in hierdie studie geraak nie. Broeivolstruise in hierdie studie het nie die vermoë gehad om hul voerinname te beheer by enige dieët energievlak soos gebruik nie. Die aantal nutriënte wat in die eiers neergelê is, het geen bydrae tot die reproduksievermoë van die wyfie gehad nie. Die studie het verder bewys dat die gemiddelde frekwensie van eier-lê by wyfies onafhanklik was by dieët-energie en -proteïenvlakke (P>0.05) soos in hierdie studie gebruik. In ‘n vierde studie is die groei en ontwikkeling van die reproduksie-organe van die wyfies bestudeer tydens die aanvang van die broeiseisoen. Die hoeveelheid of konsentrasie van voedingstowwe moes bepaal word om die groei van die reproduksie-organe te ondersteun tydens die broeiseisoen, omdat hierdie organe aan eierproduksie gekoppel is. ‘n Studie is derhalwe uitgevoer om te bepaal tot watter mate die reproduksie organe groei en ontwikkel tydens die broeiseisoen. Die eerste slagting is uitgevoer op die dag van afkamp. Die ovaria, ovidukt en lewer is versamel, geweeg en ontleed. Die ovaria en ovidukt is ontleed vir ru-proteïen en vet. Geen verskille (P>0.05) is tussen die verskillende slagtings vir die gewig, ru-proteïen en vetinhoud vir beide organe opgemerk nie. Geen betekenisvolle tendens in die gewig van die ovidukt is waargeneem oor die 49-dae periode nie, maar die gewig was hoogs gekorreleerd met liggaamsmassa. Ovaria-gewig het geneig om gekorreleerd te wees met die aantal dae na afkamp. Variasie binne en buite die gewigte was baie hoog. Die aantal follikels teenwoordig is nie beïnvloed (P>0.05) deur die aantal dae na paring. Die lewers is ontleed vir ruproteïen en vet, maar geen verskille (P>0.05) is tussen die intervalle opgemerk nie, maar die gewigte van dag 0 en 49 na paring het verskil (P<0.05). Dit kan aangevoer word dat die voëls moontlik lewer reserwes gebruik het om die voedingstowwe van die dieët te supplementeer vir die ontwikkeling van die reproduksie-organe. Data uit hierdie studie kan gebruik word in ‘n optimiseringsmodel (Brand & Gous, 2006) om die voedingsbehoeftes van broeivolstruise te bepaal. Hierdie studie beveel aan dat die broeiwyfie moontlik addisionele proteïen tydens die eerste sewe weke van die broeiseisoen benodig. Resultate van Hoofstuk 4 en vorige studies is gebruik om die energie- proteïen- en aminosuurbehoefte vir eierproduksie en onderhoud van broeivolstruise te bereken. Twee metodes is gebruik om die energiebehoefte vir eierproduksie te bereken. Metaboliseerbare Energie behoefte vir eierproduksie (MEe) en effektiwiteit van ME benutting vir energie deponering in eier (ko) is onderskeidelik as 12.2 MJ (vir ‘n eier wat gemiddeld 1.4kg weeg) en 0.8 bereken. Effektiewe Energie behoefte vir eierproduksie (EEe) en onderhoud (EEm) was onderskeidelik as 15.9 MJ/dag en 17.1 MJ/dag bereken. Die gemiddelde daaglikse proteïenbehoefte (TPt) is as 175g proteïen/dag bereken. ‘n Aanduiding van die aminosuur behoefte vir onderhoud en eierproduksie word ook gegee, wat laer is as vorige studies.

Using a phenomenological approach, this study, "Killing Ostriches" sought to investigate the experience of violence in the home of a small group of young women living in the northern suburbs of Perth. Seven young women between the ages of 17-26 took part in the study. Five of these young women claimed to have experienced violence in their family of origin and the: remaining two, introduced for triangulation purposes, claimed not to have done so. The study sought, not only to explore the lived experience of violence in the home for these young women, but to also investigate their experience of youth work practice. Accounts of family violence provided indicate the significance and meaning of family violence for participants. What the study was not able to do is to provide accounts of aspects of youth work practice perceived as beneficial or detrimental by the young women involved in the study as none of them were aware of the availability of youth workers. They were unaware of other supports available to them and were also scared that if anyone found out, their situation would become intolerable. Each of these women chose not to disclose to anyone outside their immediate environment. For some of these young women I was the first person to whom they had disclosed much of their story. The study provides a better understanding of why it is that young women who have experienced violence in their family of origin do not disclose to others who might be in a position to support them and possibly stop the violence. The young women in this study were isolated from their peers and any support mechanisms that might have been available to them. The study, therefore, provides further insight into why it is that young women living in a violent environment choose to remain silent thereby maintaining the isolation associated with family violence. What is clear is that young women who have experienced violence, no matter what form that violence might have taken or where it is placed on the continuum of violence, have a need to discuss their experience with an individual they feel confident will support them according to their needs. What is also clear is that these particular young women were not aware of anyone who might fill this role. The literature shows the importance of identifying at least one attachment figure as early as possible in life, with whom a secure attachment may be developed. The women in this study have greater awareness of the issues involved in family violence than do many youth workers and other professionals to whom they might realistically go for help. What this study has shown is that there is need for further research based on the needs and experience of women, such as those involved in this study, to effectively answer the original research subquestion relating to youth work practice. It also suggests that youth work practioners should be involved in such research.

Ostrich organs/tissue/fluids were screened for plasma kallikrein-like, tissue kallikrein-like and tonin-like activity in a continuous-fluorogenic-assay system using Pro-Phe-Arg-7-amino-4-methylcoumarine, Phe- Arg-7-amino-4-methylcoumarine and Val-Leu-Arg--7-amino-4-trifluoro-methylcoumarine as substrates. Ostrich liver and kidney showed the highest specific plasma kallikrein-like activity. Ostrich adrenal glands and kidney showed the highest specific tissue kallikrein-like and tonin-like activity. Ostrich high molecular weight kininogen was purified from plasma and low molecular weight kininogen was partially purified. The N-terminal amino acid sequences of both high- and low molecular weight kininogens from ostrich plasma were determined. Ostrich plasma high molecular weight kininogen was purified as a 118 kD protein. The purified high molecular weight kininogen inhibits the cysteine proteinase papain at a ratio of one molecule HKG to two molecules of papain. Ornitho kinin-like molecules were detected in ostrich urine using reverse phase HPLC.

The aim of this research was to identify how farmers learn how to farm using pluriactive lifestyle block ostrich farmers who are part of the New Zealand ostrich industry as a case study. Ostrich farming is comparatively new to New Zealand farmers and the industry has attracted innovative individuals who have developed informal learning strategies. Ostrich farmers use other farmers as their main resource which is mainly facilitated through events organised by the New Zealand Ostrich Association (NZOA) and aimed at lifestyle block farmers. Ostrich farmers' community of practice is centred around their membership to the Association which enables farmers to come together to learn and socialise. For learning to effectively take place the key is social interaction, where ideas can be transferred between farmers. This thesis illustrates the important events and structure of the industry and how this has shaped farmer learning. Through semi-structured interviews and participant observation on a chick rearing farm I was able to gain a picture of how lifestyle block farmers balance full time off-farm employment while running stock, in an attempt to satisfy their version of the rural idyll. The industry is now in decline as most of the early players have exited the industry and it is now focused around New Zealand Ostrich Export (NZOE) goals. By exploring the period called the breeder phase which was characterised by some farmers making a fortune as ostrich farming was the 'next big thing' and the history since then, I have identified how these particular farmers have learned how to farm.

Dissertation (PhD)--University of Stellenbosch, 2004
ENGLISH ABSTRACT: Newcastle disease (NO) and mycoplasma infections in ostriches have considerable economic implications for the South African ostrich industry in that NO is a limiting factor in the export of ostrich products to the European Union and mycoplasma infections cause stock losses, reduced production, reduced hatchability and downgrading of carcasses. In the first section of this dissertation, the role of passively acquired and mucosal immunity in protection of ostrich chicks against Newcastle disease virus (NOV) was investigated. Ostrich hen serum IgG and yolk IgY were isolated and characterized, and the transfer of maternal anti-NOV antibodies to the egg yolk was determined using an enzyme-linked immunosorbent assay (ELISA). Results indicated that anti-NOV antibodies were successfully transferred from the ostrich hen to the egg yolk. In addition, ostrich IgA was isolated, characterized and rabbit anti-ostrich IgA antibodies produced and used for measuring mucosal anti- NOV IgA antibodies produced in response to mucosal vaccination. Results indicated that the live La Sota vaccine stimulates IgA production and thus mucosal immunity in ostrich chicks. In the second section of this dissertation, ostrich mycoplasmas were isolated and identified using 16S rRNA gene sequencing. These sequences indicated that ostriches carry three unique mycoplasmas, which are phylogenetically quite divergent. The 16S rRNA gene sequences of the ostrich mycoplasmas were subsequently used for the development of specific primers for the detection and diagnosis of mycoplasma infections in ostriches by PCR. The last section of this dissertation focuses on avian malaria in African penguins and the management of this disease during rehabilitation. The Foundation for the Conservation of Coastal Birds (SANCCOB) is a seabird rescue and rehabilitation centre, which is largely dedicated to the rehabilitation of diseased, injured and oiled penguins. Significant mortalities due to avian malaria occur at this facility. The aim of this study was the development of an ELISA for the purpose of assessing the natural levels of anti-Plasmodium antibodies in African penguins on entry into the SANCCOB facility and during rehabilitation. Results indicated significant increases in anti- Plasmodium antibody levels after entry, which was not influenced by oiling. Infection with malaria and not parasite recrudescence was viewed to be the cause of this increase, indicating a possible role of the SANCCOB facility in exposing penguins to avian malaria.
AFRIKAANSE OPSOMMING: Newcastlesiekte (NS) en mikoplasmainfeksies in voltruise het geweldige ekonomiese implikasies vir die Suid-Afrikaanse volstruisbedryf. Die rede hiervoor is dat NS 'n beperkende faktor in die uitvoer van volstruisprodukte na die Europese Unie is, en mikoplasmainfeksies tot kudde verliese, verlaagde produksie en uitbroei asook lae gradering van karkasse lei. In die eerste gedeelte van hierdie proefskrif is die rol van passiewe- en mukosale-immuniteit in die beskerming van volstruiskuikens teen NS virus (NSV) ondersoek. Volstruishenserum IgG en eier IgY is geïsoleer en gekarakteriseer en die oordrag van maternale anti-NSV antiliggame na die eier ondersoek met behulp van 'n 'enzyme-linked immunosorbent assay' (ELISA). Resultate het getoon dat anti-NSV antiliggame suksesvol van die hen na die eier oorgedra is. Volstruis IgA is ook geïsoleer, gekarateriseer en konyn anti-volstruis IgA antiliggame geproduseer wat gebruik is vir die bepaling van mukosale anti-NSV IgA antiliggame in reaksie op mukosale immunisering. Resultate het getoon dat lewendige La Sota entstof IgA produksie stimuleer en dus tot mukosale-immuniteit in volstruiskuikens lei. In die tweede gedeelte van hierdie proefskrif is volstruismikoplasmas geïsoleer en geïdentifiseer met behulp van 16S rRNA geenopeenvolgingsbepalings. Hierdie volgordes het getoon dat drie unieke mikoplasmas in volstruise voorkom wat filogeneties verskillend blyk te wees. Die 16S rRNA geenopeenvolgings van die volstruismikoplasmas is gebruik vir die ontwikkeling van spesifieke inleiers vir die PKR identifisering en diagnose van mikoplasmainfeksies in volstruise. Die laaste gedeelte van hierdie proefskrif fokus op voëlmalaria in die Afrika pikkewyn en die bestuur van hierdie siekte gedurende rehabilitasie. Die 'South African Foundation for the Conservation of Coastal Birds' (SANCCOB) is 'n seevoëlreddingsen rehabilitasie-sentrum vir siek, beseerde en ge-oliede pikkewyne. Hierdie sentrum het egter aansienlike vrektes as gevolg van voëlmalaria. In hierdie studie is 'n ELISA ontwikkel vir die bepaling van natuurlike anti-Plasmodium antiliggaamvlakke van pikkewyne by aankoms en tydens rehabilitasie by SANCCOB. Resultate het 'n toename in anti-Plasmodium antiliggaamvlakke getoon na toelating wat nie beïnvloed is deur olie nie. Hierdie toename kan toegeskryf word aan nuwe malariainfeksies en nie 'n heruitbraak van bestaande infeksies nie wat daarop dui dat pikkewyne aan voëlmalaria blootgestel word by die SANCCOB-sentrum.

Thesis (PhD(Agric) Animal Sciences))--University of Stellenbosch, 1988.
Farming with ostriches became established as a new stock-farming activity in South Africa around 1863. Ostrich feathers were then the only commercial product of that activity and fifty years later still held fourth place on the list of exports from South Africa - after gold, diamonds and wool (Smit, 1963). However during the world depression of 1914 - 1945 the appeal of ostrich feathers vanished and the industry collapsed. Today commercial farming with domesticated ostriches (Struthi0 camelus var. domesticus), originating from a cross (Duerden, 1910; Smit, 1963, 1984) between the South African (Struthio camelus australis) and the North African ostriches (Struthio camelus camel us), is again a rapidly expanding activity in South Africa's Little Karoo. This is the only region in the world where farming with ostriches is still encountered at a commercial scale, and although relatively small in the general stock-farming scenario, it provides a livelihood for about 400 farmers who run some 150 000 ostriches. Feathers, together with ostrich leather and meat are all prominent export products that account for foreign exchange earnings of more than R30 million. In terms of monetary value the ostrich industry has grown by more than 300% over the past decade and by al most 100% in the 1ast 5 years. This high growth rate is primarily due to the steady development of the slaughter bird industry in which leather, meat and feathers account for more than 80% of the entire industry's turnover. Ostrich products, however, are primarily exclusive fashion products, of which more than 90% is exported. Because the world market is relatively small, expansion prospects for the industry are limited and sensitive to supply and demand. To ensure the industry's continued economic well-being, ostrich research pays particular attention to production techniques that will help to improve efficiency and result in better product quality and profitability. For the purpose of increased ostrich chick production, ostrich eggs are presently being incubated in large quantities (ca 200 000 eggs per annum). However, hatching success of ostrich eggs in incubators is considerably below that of natural nests, and Burger & Bertram (1981) suggested that it may be due to high humidities (63% relative humidity) commonly used in ostrich incubators. Investigations were undertaken to measure incubation temperatures and humidities during the complete course of 41 days of natural incubation in 6 ostrich nests. In addition, the water vapor conductance of the eggs was measured, as well as the incubation water loss which in other species averages 15% of the initial egg mass and has been proposed as an optimal condition for hatching success (Ar & Rahn, 1978; Rahn 1984). The natural incubation parameters measured during these experiments were adapted and applied to conditions of artificial incubation. This improved the realized hatchability from 50 to 75%. Furthermore the intensive production and finishing of slaughter birds on complete dry meal diets under feedlot conditions is a new development which contains exceptional possibilities for the industry (Swart & Kemm, 1985). Economically and biologically, efficient diet formulation has accordingly become essential for profitable slaughter bird production. The nutritional value of feed constituents for ostriches is, however, still unknown and without it effective least cost diet formulation and programming is not possible. Present growth and finishing diets for ostriches are based on energy values of the dietary components which have been derived from poultry (Blair, Daghir, Morimoto, Peter & Taylor, 1983; Du Preez, Duckitt & Paulse, 1986) and pig values (Kemm & Ras, 1981; NRC, 1973; IAFMM, 1985). This approach may, however, result in unreal estimation of the actual nutritional value of feed constituents for ostriches, so that quantification of their nutritional value has consequently become necessary. During 1985 a multi-disciplinary research programme on ostriches was initiated, the objective being to investigate the energy metabolism and the efficiency of energy utilization in growing farm ostriches. For the purpose of these experiments all ostrich chicks were incubated in an ostrich egg incubator, maintained at a dry bulb temperature of 36°C and a wet bulb temperature of 24,0 ± 1,0°C. These temperature settings were extrapolated from the natural incubation parameters measured in the six naturally incubated nests (Swart, Rahn & De Kock, 1987; Swart & Rahn, 1987). An important aspect of the studies on energy metabolism was to determine the extent to which plant fibre is digested in various segments of the gastrointestinal tract of growing ostriches and whether these birds utilize the end products of fibre digestion, namely volatile fatty acids such as acetic acid, efficiently. The possible use of metabolizable energy to evaluate feedstuffs for ostriches was an initial aim of this study. Subsequently the effect of crude fibre or energy concentration on the digestibility of gross energy, energy loss as methane, heat expenditure, and the effect on the efficiency of ME utilization were investigated. Finally accretion patterns and the partition of metabolizable energy during growth were studied in the young ostrich chick. The findings of the studies on incubation aspects (Section 1) are presented in Chapter 2 and 3 and that of the metabolism studies (Section 2) are presented in Chapters 4, 5, 6, 7 and 8 of this dissertation.

Thesis (MSc)--University of Stellenbosch, 2006.
ENGLISH ABSTRACT: Ostrich farming is of significant economical importance in South Africa. Three ostrich mycoplasmas, Ms01, Ms02 and Ms03 have been identified previously, and were provisionally named ‘Mycoplasma struthiolus’ (Ms) after their host Struthio camelus. Ostrich mycoplasmas are the major causative organisms of respiratory diseases, and they cause stock losses, reduced production and hatchability, and downgrading of carcasses and therefore lead to large economic losses to the industry. In order to be pathogenic to their host, they need to attach through an attachment organelle, the so-called tip structure. This structure has been identified in the poultry mycoplasma, M. gallisepticum, and is made up of the adhesin GapA and adhesin-related CrmA. Currently, no ostrich mycoplasma vaccine is commercially available and for this reason the need to develop one has arisen. Therefore the first part of this study was dedicated to the identification and isolation of vaccine candidate genes in the three ostrich mycoplasmas. Four primer approaches for polymerase chain reactions (PCR’s), cloning and sequencing, were used for the identification of adhesin or adhesin-related genes from Ms01, Ms02 and Ms03. The primer approaches revealed that the target genes could not be identified due to the high diversity of sequences that were generated. Therefore sequences were also compared with those of other mycoplasma species in BLAST searches. Results showed that the most significant hit was with the human pathogen M. hominis oppD, which is located in the same operon as the membrane protein P100 involved in adhesion. Other hits were with ABC transporters which may also play a role in cytadhesion. The second part of this study was aimed at testing whether two poultry mycoplasma vaccines, M. synoviae and M. gallisepticum, can be used in ostriches to elicit immune responses until an ostrich mycoplasma vaccine has been developed. Ostriches on three farms of different age groups in the Oudsthoorn district were therefore vaccinated with these vaccines in a vaccine trial. The enzymelinked immunosorbent assay (ELISA) was used to test the level of antibody response. Results showed that both vaccines elicited an immune response in all three age groups. A high percentage of the ostriches reacted positively, which indicates that both vaccines elicit antibody responses and may therefore give protection against ostrich mycoplasma infections.
AFRIKAANSE OPSOMMING: Volstruisboerdery is ‘n belangrike ekonomiese sektor in Suid-Afrika. Drie volstruismikoplasmas, Ms01, Ms02 en Ms03, is voorheen geïdentifiseer en voorlopig ‘Mycoplasma struthiolus’ (Ms) benaam na aanleiding van hul gasheer, Struthio camelus. Volstruismikoplasmas is die grootste oorsaaklike organismes van respiratoriese siektes, kudde verliese en die afgradering van karkasse wat lei tot groot ekonomiese verliese in die volstruisbedryf. Ten einde patogenies vir die gasheer te wees, moet mikoplasmas deur middel van ‘n aanhegtingsmeganisme vasheg – die sogenaamde puntvormige struktuur. Hierdie struktuur is in die pluimvee mikoplasma M. gallisepticum geïdentifiseer, en bestaan uit aanhegting proteïen GapA en die aanhegting verwante proteïen CrmA. Tans is geen volstruismikoplasma entstof kommersieel beskikbaar nie, en derhalwe het die behoefte ontstaan om so ‘n entstof te ontwikkel. Die eerste gedeelte van hierdie studie is dus gewy aan die identifisering en isolering van entstof kandidaat gene in al drie volstruismikoplasmas. Vier inleier benaderings vir polimerase ketting reaksies (PKR), klonering asook geenopeenvolging bepalings vir die identifisering van aanhegting of aanhegting verwante gene vanuit Ms01, Ms02 en Ms03 is gebruik. Die inleier benaderings het getoon dat die teikengene nie geïdentifiseer kon word nie as gevolg van hoë variasie in die gegenereerde geenopeenvolgings. Derhalwe is geenopeenvolgings met ander mikoplasma spesies deur middel van BLAST soektogte vergelyk. Resultate het getoon dat die betekenisvolste ooreenstemming dié met die menslike patogeen M. hominis oppD was, wat deel vorm van die membraan proteïen P100 operon wat betrokke is by aanhegting. Ander ooreenstemmings sluit ABC transporters in wat moontlik betrokke kan wees by aanhegting. Die tweede gedeelte van hierdie studie het ten doel gehad om te toets of twee pluimvee mikoplasma entstowwe, M. synoviae en M. gallisepticum, gebruik kan word in volstruise om immuunresponse te ontlok tot tyd en wyl ‘n volstruismikoplasma entstof ontwikkel is. Volstruise vanaf drie plase in verskillende ouderdomsgroepe in die Oudtshoorn distrik was ingeënt met hierdie entstowwe in ‘n entstof proefneming. Die ensiem-afhanklike immuno-absorpsie essaï (ELISA) was gebruik om antiliggaam response te toets. Die resultate het getoon dat beide entstowwe immuunresponse ontlok het in al drie ouderdomsgroepe. ‘n Groot persentasie van die volstruise het positief gereageer wat ‘n aanduiding is dat beide entstowwe immuunresponse ontlok het en kan dus beskerming bied teen volstruismikoplasma infeksies.

Different management techniques were studied, at the Kromme Rhee Experimental Farm near Stellenbosch, in order to stimulate feed intake of ostrich chicks and to determine the effect on their growth rate. A first experiment was conducted to determine the effect of different dietary flavourants on the feed intake of ostrich chicks. Ostrich chicks (1-28 days of age), with no previous exposure to flavourants showed a strong preference for salty feed. Another experiment determined the effect of different colourants on the feed intake of ostrich chicks. Exposure of chicks to feed coloured artificially in different colours (green, red, blue and yellow) had no impact on the feed intake of ostrich chicks (1-28 days of age). Throughout the study the dry matter intake was the highest for the control diet, indicating that the provision of coloured feed to ostriches, as practised in this study, will not stimulate feed intake. The effect of feed processing and restriction of water availability for ostrich chicks was also examined. Extrusion reduced microbial counts in feed by 99.7 percent. Feed intake as well as average daily gain of chicks were lowered by both the pelleting and the extrusion process practised in this study. Processing did not have a positive influence on the production of ostrich chicks 6-15 weeks of age. Dry matter intake for chicks subjected to water restriction were the same as for birds receiving water ad libitum. Similarly growth rate as well as feed conversion ratio was not effected by restriction of water, as practised in this study. Another technique studied was to determine the effect of 24h artificial light on feed intake, growth and the behaviour of ostrich chicks (1-28 days of age). A Timeactivity budget revealed that chicks subjected to 24 hours of light spent more time eating (14.7 percent) than those subjected to normal day and night cycles (11.4 percent). In spite of this, no significant difference in feed intake, growth rate and feed conversion ratio was observed for ostrich chicks subjected to different light regimes. The effect of different dietary salt levels on the production of ostrich chicks (8-12 weeks of age) was also determined. The performance of chicks was the best on a diet with a salt inclusion of 1.4 percent.

This set of experiments evaluated the physiological responses of intensively managed ostriches to L-carnitine. In experiment 1, 32 female and 16 male Zimbabwean Blue Neck and South African Black Neck breeders (n=48 of each sub-species; eight years old), were investigated in 16 breeder units of two females and one male (Trio), in a completely randomised design within four treatments and four replicates over an 8-month period during the breeding season. The same basal diet was fed supplemented with 0 (T0, control), 125 (T125), 250 (T250) or 600 (T600) mg/kg L-carnitine. T600 improved the egg production percentage, egg fertility percentage and the hatchability of set eggs for Black-Necks and Blue-Necks, respectively, and the hatchability of fertile eggs in Black Necks. L-carnitine did not affect egg shape index, defective eggs, egg weight, embryonic and post-hatch mortality. In experiment 2, 12 Black Neck males (5.5 years old) were allocated to three treatments (T0, T250 and T500) and four replicates. Semen samples were collected once a month over three months. L-carnitine had a significant effect on semen volume, sperm motility, live sperm percentage and sperm count, but had no significant effect on abnormal sperm percentage. In experiment 3, 32 day-old Black Neck ostrich chicks were allocated to treatments T0, T125, T250 and T600 with four replicates of two chicks. Chicks were vaccinated against inactive Newcastle Disease (ND) vaccine at day 30 as primary, and at day 51 as booster immunisation. ND antibody responses in the sera were monitored over three phases at 51, 70 and 80 days. Anti-NDV antibodies were detected using a modified chicken anti-NDV enzyme-like immunosorbent assay (ELISA). The treatments and the time periods and their interactions influenced ND antibody responses. T125 and T250 had the highest level of ND antibody response compare to the other groups. There were no differences in ND antibody response between T0 and T600 as well as T125 and T250. The highest ND antibody responses were recorded at day 70. Experiment 4 was designed the same as 3, to determine chicks’ growth responses over the 60-day period. Live weight and live weight gain values of T125 and T250 did not differ from those of T0. T600 had the lowest feed conversion ratio (FCR) during the total period. Feed intake (FI) was reduced in the T125 and T600 treatments compared to T0 and T250 over the total period. T125 gave the lowest FI and FCR responses over the total period, whereas there was no difference between T0 and T250. These results suggest that dietary T600 can have a beneficial effect on egg production, fertility and hatchability in the Black and Blue Neck breeders and T250 might improve sperm quality in males. In ostrich chicks T125 and T250 had positive effects on immune responses and T125 can improve the performance by decreasing the FCR. In contrast, the suppressive effect of a high inclusion level (T600) might indicate that ostrich chicks are sensitive to high inclusion levels that could cause adverse effects.
gm2013
Animal and Wildlife Sciences
Thesis (PhD)--University of Pretoria, 2013.
Unrestricted

The aim of this study was to determine the quality of slaughtered ostrich meat and to evaluate the ostrich slaughter process, to determine whether ostrich meat are contaminated by the in-house slaughtering practices and if prevalence of microorganisms increase with the succession of the slaughter process. Furthermore, the presence of specific foodborne pathogens and spoilage organisms was explored by means of molecular and conventional methods to determine whether ostrich meat is a source of these microorganisms. Data obtained from this study provides some baseline information that could be used in future studies on system contamination and the extent of downstream processing steps in the production of ostrich meat. Antimicrobial resistance has become a growing area of concern in both human and veterinary medicine, it is therefore necessary that another aim of this study was to determine the antibiotic resistant pattern of Staphylococcus aureus in ostrich meat in order to establish whether Staphylococcus aureus strains isolated from ostrich meat samples show resistance to antibiotics

Thesis (PhD(Agric) (Animal Sciences))--Univsersity of Stellenbosch, 1992.
The anatomy of the muscles of the hindquarters of the ostrich is described and presented graphically for the purpose of the present and future studies in meat science involving the ostrich. In the past, the lack of an accurate anatomical description of this species has led to the incorrect identification of certain muscles by researchers. The process of growth is described for 51 components of the ostrich body, which includes 21 muscles and four organs. Gompertz functions were calculated to formulate growth models for these components. Acceptable goodness-of-fit was obtained for the formulated models regarding the raw skin area, mass of the head, heart, filet and other muscles as well as certain bones. No information on similar models could he found for the description of growth of individual muscles or body parts of other meat animals. However, similar growth models are available for the description of live mass changes over time. Since the general growth curve is sigmoidal it is difficult to fit accurate curves by arithmetical methods. This has led to the development of simpler linear models, which express the growth of a body part relative to the growth of the same entire body. Time based predictions of yield are thus impossible. In fact, many of these allometric equations are simply in a different mathematical form, rather than being totally different equations. Furthermore, the latter equations cannot be used to predict accurate values at the positive and negative extremes since unrealistic values are obtained. Computer programs are presented in the dissertation which can be used without modification on various species, such as fish, poultry, plants and forests, as well as micro organisms in plant pathology, food science and sewage. With the development in computer technology and by means of the suggested programs, it is possible to describe the growth process on a time scale with ease. It is also possible to estimate the mass of any body part at birth (and possibly at conception) as well as at maturity. Evidence is provided that unrealistic asymptotic values are obtained with time based linear and polynomial functions as well as with published non linear allometric models for the description of growth in the ostrich. A goodness-of-fit test for the Gompertz function is presented. It is advisable to carry out this test before fitting alternative models, since the relationship between two variables is only linear on a double log scale when both variables can be described by similar functions on a time scale. A method for the calculation of the standard error at the point where maximum growth occurs is also presented. These methods can successfully be used for any of the above mentioned species. The point at which maximum growth occurred was used to compare the muscles of the hindquarters of the ostrich with that of Merino rams. This showed that these two species differ markedly in this regard. Furthermore, it was proved that certain economically important muscles still gained weight after the optimal skin size (120 dm2) was reached at the age of ten months. It is also shown that the fat content of ostrich meat (filet) varied independently of the abdominal fat content, and that it reached a minimum value of 0.3% at the popular slaughter age of 14 months. Reliable methods for age estimation of a slaughtered bird is presented, based on the growth models. This information can be used to develop a classification system for ostrich meat and other meat animals.

Thesis (PhD)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The ostrich industry is a predominantly quantitative industry; focused mainly on the production of large numbers of slaughter birds for maximum meat and leather yield. Competing in the international market in the current economic environment necessitates a more qualitative approach. Productivity and product quality are aspects that need to be improved in order to stay competitive and economically viable. Genetic parameters for ostrich slaughter traits are lacking, however, and breeding programs are yet to be developed. Data on quantitative and qualitative production and slaughter traits from a commercial ostrich breeding flock was consequently analysed to establish the relative importance of genetic and non-genetic influences on these traits. Genetic and environmental (co)variances as well as estimates of heritability, genetic and phenotypic correlations were estimated for and among the various traits using standard software for multi-trait genetic analyses. Substantial variation, high and favourable genetic correlations as well as moderate to high heritability estimates were found among, and for distinguished body weight traits of growing ostriches. Heritability estimates of 0.14, 0.22, 0.33, 0.43 and 0.43 for 1-month, 4-month, 7-month, 10-month and 13-month-old ostrich weights were estimated in a five-trait animal model analysis. All carcass component weight traits, with the exception of the weight of the liver, showed significant genetic variation. No significant maternal permanent environmental variance was evident for these traits. Heritability estimates ranged from 0.21 (for subcutaneous fat weight) to 0.45 (for neck weight) in multi-trait analyses. The only potentially unfavourable correlation was a high genetic correlation between live weight and subcutaneous fat weight, as fat is considered as a waste product in the present system. The heritability estimates for individual muscle weights ranged from 0.14 to 0.43, while the genetic correlation between these weights and pre-slaughter live weight were all positive, ranging from 0.59 to 0.82. When meat quality traits were analysed it was evident that lightness (L*) and ultimate pH (pHu) showed significant genetic variation, with heritability estimates of 0.37 and 0.42, respectively. L* and pHu were negatively correlated (-0.65 ± 0.19). Since pH is an indicator of various meat quality parameters, it could be considered as an appropriate selection criterion for enhanced meat quality. With the exception of skin grading and crown length, all quantitative and qualitative skin traits showed significant genetic variation. Nodule traits were accordingly moderate to highly heritable. A negative, but favourable, correlation between weight and hair follicle score was ascertained, as hair follicles is a defect that should be selected against. This study demonstrated that sufficient genetic variation exists for most slaughter traits to allow sustained genetic progress for these traits, should it be desired as part of the overall selection objective. Combining some of the current economically important slaughter traits in a provisional selection index, it was clear that weight and crust skin size contributed most to monetary gain (approximately 54 and 38%, respectively). It was also demonstrated with this simple index that monetary gains in slaughter bird production should be easy to achieve at all levels of production performance and data recording.
AFRIKAANSE OPSOMMING: Die volstruisbedryf is hoofsaaklik ‘n kwantitatiewe bedryf wat meerendeels fokus op die produksie van groot getalle slagvolstruise vir die produksie van vleis en leer. Siende dat die bedryf hoofsaaklik op uitvoere fokus, word aanvaar dat ‘n verandering in strategie na ‘n meer kwalitatiewe benadering nodig is, in ag geneem die huidige ekonomiese situasie en marktoestande. Produktiwiteit sowel as produkgehalte moet in ag geneem word vir die bedryf om lewensvatbaar te bly. Daar is egter ‘n gebrek aan genetiese parameters vir volstruisslageienskappe, terwyl doeltreffende teeltstelsels nog ontwikkel moet word. Data van kwantitatiewe en kwalitatiewe produksie- en slageienskappe is gevolglik van ‘n kommersiële volstruis teeltkudde verkry en ontleed om die relatiewe belang van genetiese en nie-genetiese effekte op die eienskappe te kwantifiseer. Genetiese- en omgewings (ko)variansies, asook beramings van oorerflikheid sowel as genetiese en fenotipiese korrelasies, is vervolgens vir en tussen die onderskeie eienskappe beraam deur van standaard sagteware vir veelvuldige-eienskap genetiese ontledings gebruik te maak. Aansienlike variasie, hoë en meestal gunstige korrelasies, sowel as matige tot hoë oorerflikhede, is tussen en vir die onderskeie ligaamsgewigte van groeiende volstruise gevind. Oorerflikheidsberamings van 0.14, 0.22, 0.33, 0.43 en 0.43 is vir 1-maand, 4-maande, 7-maande, 10-maande en 13-maande-oue volstruise in ‘n vyf-eienskap dieremodel ontleding gekry. Alle karkaskomponentgewigte, met die uitsondering van die gewig van die lewer, het betekenisvolle genetiese variasie getoon. Oorerflikheidsberamings het tussen 0.21 (vir onderhuidse vetgewig) en 0.45 (vir nekgewig) gevarieer in veelvuldige-eienskapontledings. Die enigste moontlike ongunstige korrelasie was tussen liggaamsgewig en onderhuidse vetgewig, siende dat vet as ‘n afvalproduk gereken word in die huidige stelsel. Die oorerflikhede van die gewigte van indiwiduele spiere het van 0.14 tot 0.43 gevarieer, terwyl die genetiese korrelsies tussen hierdie gewigte en voorslaggewig deurgaans positief was, met waardes wat van 0.59 tot 0.82 gewissel het. Tydens die ontleding van vleisgehalte eienskappe was dit duidelik dat ligtheid (L*) en uiteindelike pH (pHu) genetiese variasie getoon het, met oorerflikheidsberamings van onderskeidelik 0.37 en 0.42. L* en pHu was negatief gekorreleerd op die genetiese vlak (-0.65 ± 0.19). Aangesien pH ‘n aanduiding is van verskeie vleisgehalteparameters, kan dit moontlik as ‘n indirekte seleksie-kriterium vir verbeterde vleisgehalte gesien word. Alle kwantitatiewe en kwalitatiewe veleienskappe het genetiese variasie getoon, met die uitsondering van velgradering en kroonlengte. Knoppie-eienskappe van die veerfollikels op die vel was ooreenstemmend matig tot hoog oorerflik. ‘n Negatiewe, maar gunstige, genetiese korrelasie is tussen liggaamsgewig en haarfollikelpunt beraam, siende dat haarfollikels ‘n defek is waarteen daar geselekteer moet word. Hierdie studie dui op voldoende genetiese variasie vir die meeste slageienskappe om voldoende genetiese vordering te verseker indien dit verlang sou word. Somminge van hierdie eienskappe wat tans van ekonomiese belang is, is vervolgens in ‘n voorlopige seleksie-indeks gekombineer. Dit was duidelik dat liggaamsgewig en velgrootte die meeste tot monetêre vordering bygedra het (onderskeidelik ongeveer 54 en 38%). Dit is vervolgens aangetoon dat monetêre vordering maklik haalbaar behoort te wees op alle vlakke van produksieprestasie en data-aantekening.

The South African ostrich industry is presently characterised by a drastic decline in the slaughter price of slaughter birds, due to the drop in the price of meat as well as leather. As a result, the economic viability of ostrich farming is severely hampered by these developments, and many generally accepted industry practices have to be reviewed. Among the practices under review is the possibility of slaughtering ostriches at an earlier age than the traditional slaughter age of 12 - 14 months, in order to minimise feed costs and the incidence of damage to the skin. However, little information is available on the effect of the slaughter age on the yield and quality of the economically important end-products. The effect of slaughter age on production and the economic viability of a commercially intensive ostrich production system was consequently evaluated in a completely randomised experimental design involving two batches (n= 81 and n= 94) of ostriches. The experiments took place at Kromme Rhee experimental farm of the Elsenburg Research Centre near Stellenbosch. The birds were subject to experimental treatment at the age of 4 months (n= 81, from May 2004 to March 2005) and 6 months (n= 94, from August 2004 to August 2005) respectively. The ostriches were randomly divided into 10 groups of between 16 and 20 birds per group. Standard production practices, as applied in an intensive ostrich production unit, were implemented. Clean drinking water and self-mixed grower diet (min 15 percent crude protein, 0.68 percent lysine and 11.4 MJ ME per kg feed) and finisher diet (min 14 percent crude protein, 0.55 percent lysine and 9.8 MJ ME per kg feed) were provided ad libitum to the birds. Birds were slaughtered at the ages of 8.5, 10.5, 12.5, 14.5, and 16.5 months respectively. Data on feed intake and yields of cold carcass, crust skin size, skin grade and total feathers was recorded for birds slaughtered at the respective ages. Data was analysed according to the analysis of variances. Values for meat yield, skin size yield and feed intake were predicted by regression analysis based on experimental values. Industry figures and norms were used as proxy for other production inputs and costs. A gross margin type analysis was performed to evaluate the effect of different slaughter ages on the profitability of each production system. There was a positive correlation between age and feed intake (r2= 0.40), slaughter weight (r2= 0.97), cold carcass yield (r2= 0.48), skin surface area (r2= 0.39), skin grade (r2= 0.19) and total yield of feathers (r2= 0.29). The dry skin grade showed deterioration as slaughter age was prolonged. Highly significant differences (P< 0.01) in slaughter weight, cold carcass yield, skin surface area, dry skin grade and total feathers were detected at the different slaughter ages. There were no significant differences (P> 0.05) with respect to gender for slaughter weight, skin surface area and dry skin grade within the different age groups. Males had significantly higher (P< 0.05) cold carcass yield and total feather yield than their female counterparts. From this study it can be concluded that an increase in slaughter age significantly increases feed intake, slaughter weight, cold carcass yield, and skin surface area. It is also clear that an increase in slaughter age can be detrimental to dry skin grade. The relative income contribution of the three main products (skin: meat: feathers) occurred in a ratio of 47:53:0, 52:47:1, 47:50:3, 44:51:5, 39:56:5 at the respective slaughter ages. Total income revealed an increase of 26 percent from 8.5 to 10.5 months slaughtering, an increase of 4 percent between 10.5 and 12.5 months, and an increase of 11 percent between 12.5 and 14.5 months. The income dropped by 0.3 percent between 14.5 and 16.5 months slaughtering. Total costs increased with slaughter age, particularly feed costs which showed an increase (at a decreasing rate) between the different slaughter ages. The margin above specified cost per bird was the highest for birds slaughtered at the age of 10.5 months. The margin above cost showed a steady decline as birds were slaughtered at higher ages. Slaughtering at 16.5 months revealed a negative margin. To compare the effect of differences in time span on different slaughter age regimes, margin above costs for each system over 5 years were discounted to a present value. In this study, with current feed costs and income from end products, slaughtering at 10.5 months revealed the highest present value for the margin above cost. Furthermore, slaughtering at 16.5 months revealed a negative present value on the margin above cost after 5 years. Financial viability calculations are relevant and valid for data obtained in this case study. Financial viability is however case-specific and may vary between producers, depending on their individual management practices, production systems and cost structures. Results from this study may be of significant value to managerial decision-making in the ostrich industry.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: The production and export of ostrich meat from southern Africa, to especially the European Union, are increasing rapidly due to the healthy nature of ostrich meat. The European Union has very high standards when importing food products, and it is inevitable that more emphasis is being placed on the production of high quality ostrich meat. Another aspect also of concern to consumers, is the welfare of animals prior to slaughter, and this forces producers to look at ways to decrease stress of animals during the ante-mortem period. Research regarding the effect of stress during the ante-mortem period, and as a result, on meat quality, haematology and weight loss in ostriches, is lacking and thus the purpose of this study was to investigate the effect of various transport distances, travel conditions and different birds on these factors. Ante-mortem stress was measured using serum corticosterone levels (ng/ml), heterophil: lymphocyte (H:L) ratio, white blood cell (WBC) count, aspartate aminotransferase (AST) and creatine kinase (CK), as well as the rate and extent of pH decline in the M. gastrocnemius. Special emphasis was also placed on the meat quality parameters drip loss, cooking loss, colour and Warner-Bratzler shear force (kg/1.27 cm diameter). Live weight losses, as well as carcass weight and weight of bruises cut off from each bird were also recorded during various stages of the trials. The effect of transport distance on the meat quality of ostriches was investigated. Ultimate pHu measurements were taken at 24 hours post-mortem. The muscles of the ostriches from the control group (i.e. birds that were not transported prior to slaughter) had a lower mean pHu (5.77 ± 0.053) than birds that travelled 60 (5.93 ± 0.053) and 600 km (6.11 ± 0.053), respectively. Differences in meat drip loss percentage were also observed between the three treatments. The birds in the control group (0.40 ± 0.07 %) had the lowest meat drip loss percentage compared to the birds that travelled 60 km (treatment C) (1.36 ± 0.07 %) and 600 km (treatment B) (0.97 ± 0.07 %), respectively, to a commcerical ostrich abattoir. Ostriches that were transported for 600 km (8.13 ± 1.16 %) had a greater percentage live weight loss during the antemortem period than birds that travelled a distance of 60 km (2.4 ± 2.185 %) to the abattoir, although both groups were deprived of feed for the same period. When the haematology of the groups that travelled different distances was compared at various time intervals in the ante-mortem period, both groups of birds experienced significant increases in WBC, s-AST and s-CK. An increased H:L ratio from pre-transport to post-transport was only evident in the birds that travelled 600 km (treatment B). However, the birds that travelled 60 km were the only group of birds that had significant elevated serum corticosterone levels during the ante-mortem period. The increase in the various blood parameters indicates severe physical stress, which negatively affected meat quality. Another trial also investigated the effect of various farming systems and transport on meat quality and bruising of ostrich carcasses. Ostriches were raised in three different farming systems, i.e. feedlot -, semiintensive - and free range conditions. Other factors that could maybe impact on stress susceptibility, such as road conditions, floorspace and floor type were also investigated. A significant difference in meat pHu was found between ostriches that were raised in a feedlot (5.95 ± 0.018) and semi-intensive (6.04 ± 0.033) environment. The feedlot birds also had the greatest percentage of carcass weight removed due to bruising. The free range birds were the birds that had the lowest floor density per birds and also had the least amount of bruising on their carcasses. Incidently the other two groups (feedlot and semi intensive) were the birds that travelled on the same type of road (mountain pass) in a truck with rubber flooring whilst the free range birds travelled on a straight road in trucks with metal grid floors.The results indicate that the type of farming system didn’t have a significant influence on meat quality of ostriches, but that factors such as road conditions, flooring and bird density did play a significant role in the incidence of bruises and injuries obtained during transport.
AFRIKAANSE OPSOMMING: Die produksie en uitvoer van volstruisvleis vanuit suidelike Afrika, na veral die Europese Unie, is gedurig aan die toeneem as gevolg van die gesonde aard van volstruisvleis. Die Europese Unie het baie hoë standaarde wanneer dit kom by die invoer van voedselprodukte en dit is onvermydelik dat meer klem op die produksie van hoë gehalte volstruisvleis gelê word. ʼn Ander aspek wat ook kommer wek by verbruikers is die welstand van diere voor slagting en hierdie aspek noodsaak produsente om te kyk na maniere om stres te beperk tydens die periode voor slagting. Navorsing rakende die effek van stres tydens die ante-mortem periode, asook vleiskwaliteit, hematologie en gewigsverlies in volstruise as gevolg van vervoer, ontbreek. Die doel van die studie was dus om die invloed van verskillende vervoerafstande, vervoersomstandighede en tipe produksiesisteme op volstruise se stresrespons te ondersoek. Die omvang van ante-mortem stres is bepaal deur die serum-kortikosteroon vlakke (ng/ml), heterofiel: limfosiet (H:L) ratio, witbloedsel (WBS) telling, aspartaat aminotransferase AST en creatien kinase CK, asook die tempo en vlak van pH-daling in die M. gastrocnemius, te meet. Spesiale klem is gelê op die vleisgehalte parameters kookverlies, drupverlies, kleur en Warner-Bratzler-skeurwaardes (kg/1.27 cm deursnee). Gewigsverlies is aangeteken op verskillende stadiums tydens die proewe. Karkasgewigte en die hoeveelheid gewig afgesny van elke volstruiskarkas a.g.v. kneusings is ook bepaal. Die eerste studie het die invloed van vervoerafstand op vleiskwaliteit van slagvolstruise ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies, taaiheid en kleur is ondersoek. Die pHu metings is op 24 uur post-mortem geneem. Slagvolstruise in die kontrole groep (d.i. -volstruise wat nie voor slagting vervoer is nie) het ’n laer vleis pHu (5.77 ± 0.05) gehad as voëls wat onderskeidelik 60 km (5.93 ± 0.05) en 600 km (6.11 ± 0.05) ver vervoer is. Verskille in persentasie dripverlies is gesien tussen die vleis van die voëls wat nie vervoer is nie (0.40 ± 0.07 %) en die voëls wat 60 km (1.36 ± 0.07 %) en 600 km ver (0.97 ± 0.07 %) onderskeidelik vervoer is. Volstruise wat vir 600 km (8.13 ± 1.16 %) vervoer is, het ‘n groter persentasie lewende gewig tydens die ante-mortem periode as voëls wat 60 km (2.4 ± 2.19 %) ver vervoer is na die abattoir, verloor, al was beide groepe weerhou van voer vir dieselfde tydperk. Beide groepe wat vervoer is (60 en 600 km) het merkbare toenames in witbloedsel (WBS) tellings, s-AST’s en s-CK’s getoon tydens die ante-mortem periode. Daar is slegs ʼn toename in H:L ratio (ʼn indikator van stres) van voor vervoer tot na vervoer gesien in die voëls wat 600 km vervoer is. Daarteenoor was die voëls wat slegs 60 km vervoer is die enigste voëls wat ʼn toename in korticosteroon vlakke getoon het gedurende die ante-mortem periode. Die toenames is heel moontlik ‘n aanduiding van erge fisiese stres wat ‘n negatiewe effek op vleiskwaliteit het. Die tweede studie het die effek van verskillende produksiesisteme en die stress respons van die verskillende groepe slagvolstuise op vervoer ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies en taaiheid is ondersoek. Die hoeveelheid kneusings per volstruis is ook gemeet. Daar was ‘n beduidende verskil (P = 0.009) tussen die pHu van die voerkraal (5.95 ± 0.018) en semi- intensiewe (6.04 ± 0.033) volstruise. Die voerkraal volstruise se vleis het die grootste drip- en kookverliese gehad in vergelyking met die ander twee groepe (semi-intensiewe en ekstensiewe) terwyl die ekstensiewe volstruise die taaiste vleis gehad het. Die voerkraalvoëls het ook die grootste persentasie karkasgewig verloor a.g.v. kneusings wat afgesny is. Die ekstensiewe voëls het die laagste vloer digtheid per volstruis gehad asook die minste kneusings. Die ander twee groepe (voerkraal en semi intensief) was die groepe wat op dieselfde pad vervoer is (bergpas) in vragmotors wat rubber vloere gehad het terwyl die ekstensiewe voêls op ‘n reguit pad vervoer is in ‘n vragmotor met ‘n metaal oppervlakte. Die resultate van die studie is ‘n aanduiding dat die tipe plaassisteem nie ‘n groot impak op die hoeveelheid akute stres ervaar deur die voëls tydens vervoer gehad het of gevolglik op die vleiskwaliteit van die volstruise nie, maar dat faktore soos pad toestand, tipe vloer en voëldigtheid wel ‘n wesenlike rol speel in die voorkoms van kneusings en beserings opgedoen tydens vervoer.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.
Includes bibliography.
ENGLISH ABSTRACT: The ostrich industry has overcome many challenges since it originated. However, it is still vulnerable to sudden changes in customer preferences and economic cycles. As feed costs are the greatest expense in ostrich production, optimising feed formulations is vital. This will be possible if the growth and development of the ostrich can be simulated by modelling software. Various studies were conducted to describe ostrich growth in the form of equations that can be used in modelling software to increase the accuracy of predictions. In the first study, birds were given the choice of four diets with varying energy (8.5 or 13.5 MJ ME/kg feed) and protein (180 or 120 g/kg feed) levels. The birds preferred the high density diet (high energy and protein) in each growth phase. A growth curve of assumed optimal growth was constructed. The chemical fractions of the body were shown to increase non-linearly with advancing age and equations were established to predict the change of the body composition over time. In the second trial, birds received a formulated growth diet and were fed according to their nutrient requirements. Growth data was collected on the separate body components of maturing birds. Feather and skin nodule growth was defined for birds hatched in the summer. Allometric equations were set up to determine, predict and model the ostrich skin size and skin weight, some bones, some organs and the commercially valuable muscles through the growth cycle. The final trial was conducted to determine the effect of diet density (energy and amino acid level) on the growth of ostrich body components. A four-stage, 3 x 5 (energy x protein) factorial design was developed with varying energy and protein feeding regimes. Protein (amino acid) level had no influence on body component growth. Energy level had no effect on feather growth, skin nodule growth, bone and organ growth and muscle growth. Increased levels of dietary energy increased the skin size and skin weight. Increasing the dietary energy level also had a significant effect on the total body fat of the birds. Allometric equations were set up for each variable to predict the effect of diet on ostrich growth. Results in this study provide a framework for simulation modelling. Predicting ostrich growth and development is paramount to accurate diet formulations and lower feeding costs.
AFRIKAANSE OPSOMMING: Die volstruisindustrie het reeds vele struikelblokke oorkom, maar bly steeds kwesbaar vir skielike veranderinge in die ekonomiese klimaat asook in die voorkeure van die verbruiker. Een van die belangrikste insetkostes in volstruisproduksie is voer en daarom is dit noodsaaklik om voerformulerings te optimiseer. Die doel van hierdie tesis was om by te dra tot die ontwikkeling van modellering sagteware wat die groei en ontwikkeling van die volstruis naboots. Die spesifieke doel was om volstruisgroei te bestudeer en te bespreek deur middel van vergelykings wat gebruik kan word om die akkuraatheid van die simulasiemodelle te verhoog. Tydens die eerste studie is die voëls die keuse van vier diëte gegee waarvan die energie- (8.5 of 13.5 MJ ME/kg voer) en proteïen- (180 of 120 g/kg voer) vlakke verskil het. Die voëls het in die hoëdigtheid voer (hoog in energie en proteïen) in elke groeifase gekies. Uit hierdie data, wat aanvaar is om optimale groei te verteenwoordig, is ‘n groeikurwe gekonstrueer wat getoon het dat die chemise komponente van die liggaam nie-linieêr toegeneem het oor tyd. Vergelykings is hieruit afgelei wat die verandering in die liggaamsamestelling oor tyd kan voorspel. In die tweede studie het die voëls ʼn vier-fase geformuleerde groeidieët ontvang en is na gelang van hulle voedings behoeftes gevoer. Groeidata is ingesamel van die individuele liggaams-komponente van die groeiende volstruise. Veer- en velgroei is gedefinieer vir die voëls wat in die somer uitgebroei het. Allometriese vergelykings is opgestel om te bepaal hoe die volstruis se velgrootte, velgewig, sekere bene en organe, asook die kommersiële belangrike spiere gedurende die groei-siklus verander. Die finale studie is uitgevoer om die effek van voedingsvlak (energie- en aminosuurvlak) op die groei van die volstruis se liggaamskomponente te bepaal. ʼn Vier-fase, 3 x 5 (energie x proteïen) faktoriale ontwerp is gebruik met veranderende energie- en proteïenvlakke. Proteïen- (aminosuur) vlakke het geen invloed op die groei van die liggaamskomponente gehad nie. Energievlak het geen effek op die veer-, vel-, velknoppie-, been-, organe- en spiergroei gehad nie. Toenemende vlakke van energie het wel gelei tot ʼn toename in die velgrootte en massa. Die toename in voedingsengergie-vlakke het ook ʼn betekenisvolle effek op die totale liggaamsvet van die voëls gehad. Allometriese vergelykings is opgestel vir elk van die veranderlikes om die effek van dieët op elke komponent van die volstruis te bepaal. Die resultate van hierdie studies verskaf ‘n raamwerk vir die simulering en modellering van die groei en ontwikkeling van die volstruis. Akkurate voorspellings van die groei en ontwikkeling van die volstruis is noodsaaklik vir akkurate dieëtformulering en verlaagde voedingskostes.

This study reports the isolation, purification and partial characterisation of the ostrich serpin, a2AP, as well as its target enzyme, ostrich plasmin, in its active and inactive proenzyme, viz. plasminogen, forms. Three different procedures were undertaken to isolate and purify ostrich a2AP. The first one involved L-lysine-Sepharose chromatography, ammonium sulfate fractionation, ion-exchange chromatography on Toyopearl Super-Q 650S, and ostrich plasminogen-Sepharose affinity chromatography. The second procedure replaced the latter chromatographic step with gel filtration on Sephadex G-200 and hydroxylapatite chromatography, while the third one employed instead the theoretically more efficient LBSI-Sepharose chromatographic step. The third procedure yielded purified ostrich a2AP, but the degree of purity and yield were relatively low. Ostrich plasminogen was highly purified after L-lysine-Sepharose chromatography and ostrich plasmin was obtained by the urokinase-activation of the purified ostrich plasminogen Ostrich a2AP revealed an Mr of 77-84 K and two isoelectric forms of pI 3.85 and 6.18. Nterminal sequence analysis showed ostrich a2AP to have only 2 out of 11 residues in common with both those of human and bovine a2AP. Ostrich a2AP showed the largest inhibitory effects on ostrich plasmin, followed by comm. bovine chymotrypsin, trypsin and plasmin, in that order, and it appeared to be a much less potent plasmin inhibitor than bovine aprotinin, but a much more potent one than the synthetic inhibitors, DFP and EACA. Ostrich plasminogen showed an Mr of 92 K and multiple isoelectric forms (~7) in the pI range 6.01-9.18, with a major one of pI 6.01. It showed a total of 775 amino acid residues and its N-terminal sequence showed ~53 percent identity with those of human, rabbit, cat, and ox plasminogens. Ostrich plasmin revealed an Mr of 78 K, two isoelectric forms of pI 4.07 and 6.01, and a total of 638 amino acid residues. N-terminal sequence analysis showed that 2-4 residues are identical to the 5 of human, cat, dog, rabbit, and ox plasmins. The pH and temperature optima of ostrich plasmin were determined as 8.0 and 40 oC, respectively. The thermodynamic and kinetic parameters of ostrich plasmin were computed, and plasmin was shown to prefer Lys to Arg residues in the S1 position. In conclusion, ostrich a2AP, plasminogen and plasmin showed definite similarities to their mammalian counterparts, but there were also significant differences.

Most descriptions of the ostrich oropharynx and oesophagus are superficial and supply little meaningful morphological data. It was therefore the aim of this study to address this deficiency by means of a macroscopic and histological study of this region. The results were supplemented by data obtained by scanning electron microscopy. Macroscopic observations confirmed that in the ostrich the oral and pharyngeal cavities formed a single structure and could not be separated using visual criteria. The most obvious components observed in the roof of the oropharynx were the palate, the choana, the infundibular cleft and the pharyngeal folds, and on the floor, the interramal region, the tongue and the laryngeal mound. The prominent median longitudinal fold running along the palate and the numerous folds in the interrammal region of the floor contained a concentration of Herbst (Pacinian) corpuscles. The ramphotheca forming the rim of the oral cavity carried a sharp tomium along the rostral aspect of the mouth. which would assist the ostrich in tearing off plant material. It was further observed that both the roof and floor of the oropharynx could be macroscopically divided into two regions based on colour differences in the mucosa. The pale rostral regions were lined by a keratinized stratified squamous epithelium whereas the darker, more caudally positioned regions demonstrated a thicker non-keratinised epithelium and, in the case of the roof, a glandular layer. None of the regions of the upper digestive tract sampled revealed structures resembling taste buds and it would appear as if taste plays no role in the selection of food in the ostrich. The presence of large numbers of Herbst corpuscles in the palate may indicate the importance of texture in the selection of food in this species. In addition to confirming the folded nature of the ostrich tongue, this study revealed that the deep pouch formed by the dorsal tongue fold is further subdivided by a smaller secondary fold into dorsal and ventral recesses. The function of this structural adaptation is unclear but the large increase in surface area produced by the folds, and by virtue of the numerous mucous producing glands found in the mucosa, would presumably enhance mucous production and secretion required for ingesting often dry and difficult to swallow plant material. In addition to the tongue, the entire caudal aspect of the oropharynx was well-equipped with glandular tissue. Other adaptations for swallowing food included the presence of a highly folded mucosa in the interramal region which would indicate that the floor of the oral cavity in the ostrich is capable of a certain degree of distension to accommodate the accumulation of food in the oral cavity prior to swallowing. In similar fashion the longitudinal mucosal folds present throughout the oesophagus, as in other avian species, would also allow for distension of this organ when swallowing bulky food items. The pharyngeal folds that lie caudal to and around the opening of the Eustachian tubes in ratites are often referred to as the “tonsils” although no histological information has been presented to support this observation. This study revealed that the pharyngeal folds are filled with masses of diffuse and nodular lymphatic tissue and that epithelial folds emanating from the infundibular cleft and retropharyngeal recess formed tonsillar crypts surrounded by the lymphatic tissue. It has been well documented that in most species of birds papillae are found throughout the oropharynx. Papillae have also been described in ratites, mainly on the tongue and at the caudal aspect of the larynx. Whether the projections observed on the laryngeal mound of the ostrich in this study can be viewed as pharyngeal papillae remains debatable. Likewise, the lingual papillae seen in the ostrich were poorly developed and rudimentary. Compared to other birds, therefore, it is clear that the oropharynx of the ostrich is poorly equipped with papillae. This study confirmed that the hyobranchial apparatus consists of both central and paired caudo-lateral components, the former represented by the paraglossum and fused basihyale and urohyale, and the latter by the ceratobranchiale and the epibranchiale. The most important finding was that the paraglossum of the ostrich consisted of paired caudo-laterally directed cartilages that were connected rostrally to each other by fibrous connective tissue, and which supported the ventro-lateral aspect of the tongue. This information on the paraglossum has not previously been reported. The horns of the hyobranchial apparatus did not pass close to the skull as previously reported but in fact curved downwards away from the skull. The larynx consisted of the cricoid, procricoid and two arytenoid cartilages as is found in birds in general. It can be concluded that the present study, in addition to confirming the basic features of the oropharynx previously described for the ostrich, clarified the contradictory information presented in the literature and also provided new, unreported morphological data, some of which may be important when studying nutrition in these birds.
Dissertation (MSc)--University of Pretoria, 2008.
Anatomy and Physiology
unrestricted

The research program addressed in this study was to do an analysis of the potentials of the marketing of ostrich meat in the South African market. Being the world leader in the ostrich industry, the research’s emphasis was to establish reasons why the meat industry does not explore the South African meat market. To achieve this object, a literature study to determine the key components of the current situation was undertaken and used as a theoretical model to analyse the current situation in the market as well as in the ostrich industry. In addition to the literature study, an empirical study was conducted to identify some critical issues that have an influence on the potential of the domestic market. The survey method used, based on the key components gained from the literature study, consisted of an in-depth scan of the macro-environment and thorough investigation of the target industry. The investigation involved using the Internet and World Wide Web, print media, personal interviews and telephonic interviews. The result of the literature study was finally combined with the results of the empirical study and some recommendations were made. The recommendations were applicable to the ostrich industry in so far that implementing some plans for the meat industry can have serious consequences for the other products of the ostrich industry

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.
Includes bibliography.
ENGLISH ABSTRACT: A study was conducted to characterize the three ostrich breeds available as genetic resource in South Africa, namely the South African Black (SAB), Zimbabwean Blue (ZB) and the Kenyan Redneck (KR), and their respective crosses. Growth, slaughter traits and reproduction of these ostriches were recorded at Oudtshoorn Research Farm in the Western Cape of South Africa. Individual non-linear regressions (Gompertz) were fitted to the data of 390 purebred and 41 crossbred ostriches, using the SAS NLIN function. Heterosis was estimated for each parameter of the Gompertz model. The estimated adult weight (Aparameter) of the ZB (147 kg) and the KR breeds (148 kg) were higher than that of the SAB breed (129 kg). The overall growth rate (B-parameter) of the ZB breed (0.0075) and the SAB breed (0.0080) was lower than that of the KR (0.0150). The age at maximum weight gain (C-parameter) was higher for the ZB breed (226 days) compared to the SAB (198 days) and the KR (194 days). Heterosis for the A-parameter was estimated at -6.2% and at -12% for the C-parameter. The slaughter traits studied were slaughter weight (SLW), carcass weight (CW), dressing percentage (DP), fan fillet weight (FFW), pH0, pH24, drip loss % (DL%), cooking loss % (CL%), tenderness and meat colour traits. Differences were observed between the means for SLW of the SAB (86.5 kg) and ZB (93.9 kg). Mean DP of the KR breed (52.5%) was increased relative to the low DP of their SAB contemporaries (48.8%). The sire lines (ZB and KR) and crosses were heavier than the SAB (dam line), whereas the crosses resembled the dam line for meat quality traits. Means for pH24 also differed, with higher values for the sire lines (ZB – 6.36; KR – 6.4) relative to the SAB (5.85). The instrumental b* colour value also differed between the SAB (9.4) and KR (6.9). Records used for assessing the reproduction and body measurements of purebred and crossbred dams were 428 in total. Traits analyzed were, total egg production (TEP), the number of fertile eggs, number dead in shell chicks, hatchability and chick production (CP), the time to lay, live weight, front chest circumferences as well as tail circumference. The ZB and KR were heavier in live weight and of larger body measurements than the SAB, whereas the SAB exhibited superior reproduction performance in comparison with the ZB and KR breeds. Derived heterosis estimates amounted to 2.2% for tail circumference, 12% for TEP, 12% for hatchability and 19% for CP. Genetic variation between and within the breeds were determined utilizing 19 microsatellite markers. Significant molecular genetic differences were observed between the three breeds. The SAB and ZB (Fst = 0.10 and Nei = 0.49) were genetically most similar, whereas the genetic distance between the KR and ZB breeds were furthest (Fst = 0.13 and Nei = 0.61). The SAB breed exhibited the highest heterozygosity within its population and the ZB the lowest heterozygosity. These results contribute to a better understanding of the utilization of the distinct ostrich breeds for commercial production.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die verskille tussen drie volstruisrasse wat tans in Suid Afrika mee geboer word te karakteriseer, naamlik die “South African Black” (SAB), “Zimbabwean Blue” (ZB) en die “Kenyan Redneck” (KR) en hulle onderskeie kruisse. Rekords van die groei-, slag- en reproduksie eienskappe van die volstruise was by Oudtshoorn Navorsingsplaas in die Wes-Kaap aangeteken. Individuele nie-lineêre regressies (Gompertz) is op die data van 390 suiwerras en 42 kruisgeteelde volstruise gepas, met die gebruik van die “NLIN” prosedure van SAS, (2006). Heterose is beraam vir elke parameter van die Gompertz model. Die beraamde volwasse gewig (A-parameter) van die ZB (147 kg) en die KR ras (148 kg) was hoër as die van die SAB ras (129 kg). Die totale groeitempo (B-parameter) van die ZB ras (0.0075) en die SAB ras (0.0080) was laer as die van die KR (0.0150). Die ouderdom by maksimum groei (C-parameter) was hoër vir die ZB ras (226 dae) in vergelyking met die SAB (198 dae) en die KR (194 dae). Heterose vir die A-parameter was beraam teen -6.2% en teen -12% vir die C-parameter. Die slageienskappe wat ondersoek was, was slagmassa (SLW), karkasmassa (CW), uitslag persentasie (DP), “fan fillet” massa (FFW), pH0, pH24, drupverlies % (DL%), kookverlies % (CL%), sagtheid en kleureienskappe. Beduidendende verskille is waargeneem tussen die gemiddeldes vir SLW vir die SAB (86.5 kg) en ZB (93.9 kg). Gemiddelde DP van die KR ras (52.5%) was beter as die van die SAB ras (48.8%). Die mannetjielyne (ZB en KR) en die kruisse was swaarder as die SAB (wyfielyn), en die kruise was vergelykbaar met die wyfielyn vir vleiskwaliteit eienskappe. Gemiddeldes vir die pH24 het verskil, met hoër waardes vir die vaar lyne (ZB – 6.36; KR – 6.4) relatief tot die SAB (5.85). Die instrumentale b* kleurwaarde het ook verskil tussen die SAB (9.4) en KR (6.9). ‘n Totaal van 428 rekords is gebruik om reproduksie en liggaamsmetings van die suiwer en kruisteelwyfies te ondersoek. Reproduksie eienskappe ge-analiseer was: die aantal broeisels, totale eierproduksie (TEP), die aantal vrugbare eiers, die aantal kuikens dood in dop, uitbroeibaarheid, kuiken produksie (CP), tyd tot produksie van die eerste eier, volwasse gewig, voorbors omtrek, sowel as, kruisomtrek. Die ZB en KR rasse was swaarder as die SAB, en het groter liggaamsmetings gehad. Die SAB het beter reproduksie in vergelyking met die ZB- en KR rasse gehad. Heterose beramings was 2.2% vir kruisomtrek, 12% vir TEP, 12% vir uitbroeibaarheid en 19% vir CP. Genetiese variasie tussen en binne die rasse was vasgestel deur die gebruik van 19 mikrosatelliete merkers. Beduidende genetiese verskille op ‘n molekulêre vlak was waargeneem tussen die drie rasse. Die SAB en ZB (Fst = 0.10 en Nei = 0.49) was geneties meer gelyk terwyl die KR en ZB genetiese verder verwyder is (Fst = 0.13 en Nei = 0.61). Die SAB ras het die hoogste heterosigositeit binne populasie getoon, en die ZB die laagste. Hierdie resultate dra by tot ‘n beter begrip van die gebruik van die drie rasse in kommersïele produksie.

The isolation and purification of calpastatin from ostrich liver is presented, along with its physicochemical and kinetic properties. By using extraction from liver, ion-exchange chromatography on DEAE-Toyopearl, heating to 90 °C for 10 min and rechromatography on Toyopearl Super-Q 650 S, ostrich calpastatin was isolated and purified from ostrich liver. The purified intact calpastatin showed homogeneity on SDS-PAGE (Mr of 105.6 K). Amino acid analysis showed that ostrich calpastatin resembled that of rabbit liver and human erythrocyte calpastatin. An N-terminal sequence could not be obtained because the N-terminus was found to be blocked by an as yet unknown amino acid residue. The Mr values of degradative forms of ostrich liver calpastatin were determined to be 56 K and 90 K. By using PAG-IEF the pI of the intact form was determined to be 5.1. Ostrich liver calpastatin behaved characteristically like other calpastatins during kinetic analysis. Calpastatin inhibited calpain from pH 6 to 9 and was found to be unaffected by temperatures as high as 100 °C. Calpastatin also inhibited calpain activity at Ca2+ concentrations ranging from 1 to 10 mM. The inhibitor was shown to be phosphorylated because after incubation with alkaline phosphatase there was a decrease in inhibitory activity. No inhibitory effects were detected against other proteases such as chymotrypsin and trypsin, with both proteases inactivating calpastatin completely. Ostrich liver calpain was shown to have a pH optimum of 7.5 and a temperature optimum of 30 °C. In terms of its thermodynamic properties it resembled that of other ostrich proteases; DH, DS and DG being 47.07 kJ/mol, -91.1 J/mol/K and 74.237 kJ/mol, respectively. Ostrich liver calpain showed a Km of 0.14 % (w/v). The enzyme was active at both milli- and micro-molar concentrations of Ca2+. Ostrich liver calpastatin showed many physical, chemical and kinetic properties similar to those of other known calpastatins.

Eggshell of the African Ostrich, Struthio camelus, frequently occurs in African archaeological sites, some of which are beyond the limit of radiocarbon dating. In order to date those sites beyond the range of ¹⁴C dating using amino acid geochemistry, an understanding of the reaction kinetics governing amino acid chemistry must be achieved. The integrity of the eggshell matrix provides an excellent medium to investigate the kinetics of protein hydrolysis, amino acid decomposition, and isoleucine epimerization. Mathematical equations are derived from high temperature simulations of time and well-dated sites at ambient temperatures to determine rate constants for the reactions to a D/L ratio of 1.0. The reactions studied are Free and Total isoleucine epimerization, "classical" and "extended" hydrolysis, and the change in concentrations of free, bound, and total amino acids. Arrhenius plots aided in deriving the equations for each method which are then applied to predict kinetic parameters. Temperatures can be predicted within a 2°C range and time within 15% of its actual value if the appropriate method is used.

Thesis (PhD)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Mycoplasma nasistruthionis sp. nov. str. Ms03 (Ms03) is one of three Mycoplasma species that were identified from ostriches. Mycoplasmas infections have been implicated in ostrich chick mortalities, growth retardation and downgrading of ostrich carcasses. Currently there is no vaccine available for the treatment of mycoplasmosis in ostriches. This study investigated the development of DNA vaccines against Ms03 infections in ostriches. To this end, the Ms03 genome was sequenced and annotated. The vaccine candidate gene, oppA, was identified within the genome sequence and characterized before DNA vaccines containing the oppA were developed and tested. The genome of Ms03 was sequenced and the resulting 172 contigs were annotated. This dissertation presents the first Ms03 draft genome and annotation which contributed to the understanding of Ms03 as a miniature genetically independent organism. In Ms03, genome replication, cell division, RNA transcription, protein translation and glycolysis resemble that of the closely related Mycoplasma synoviae 53. Purine and pyrimidine metabolism was incomplete and de novo synthesis thereof was not possible. Amino acid synthesis in Ms03 was mostly absent and only the genes that convert aspartate to asparagine and glycine to serine were found. More importers than exporters were annotated owing to the lack of synthesis pathways in Ms03, which is typical for mycoplasmas that have parasitic life styles. Two oligopeptide permease (opp) operons were annotated within the Ms03 genome. The potential of the oppA as a vaccine candidate gene was evaluated by investigating the need for a substrate-binding domain (OppA) as part of the OppBCDF transporter within Mycoplasma species. An oppA homologue could be identified for each oppBCDF operon in all species and therefore must play an essential role in oligopeptide transport. All mycoplasmas (except for hemoplasma) had one, two or three opp operons that could be divided into three types (Type A, B and C). Each type had unique InterPro and MEME domains and motifs which together with the phylogenetic analysis suggest unique roles in their survival under different conditions. Ms03 had a Type A and a Type B opp operon, the Type A oppA was used as vaccine candidate gene. The Type A oppA was cloned and site-directed mutagenesis was used for codon correction before the mutated gene was sub-cloned into three DNA vaccine vectors. The three DNA vaccines (pCI-neo_oppA, VR1012_oppA and VR1020_oppA) were used to vaccinate ostriches and the OppA-antibody response was analysed by ELISA. The VR1020_oppA and pCI-neo_oppA constructs elicited a primary immune response in ostriches, indicating that the OppA protein was expressed in vivo and was immunogenic. This can therefore be viewed as the first step in the development of a DNA vaccine for the control of mycoplasma infections in ostriches.
AFRIKAANSE OPSOMMING: Mycoplasma nasistruthionis sp. nov. str. Ms03 (Ms03) is een van drie mikoplasma spesies wat volstruise infekteer. Mikoplasma-infeksies in volstruise veroorsaak kuiken vrektes, vertraagde groei en afgradering van volstruis karkasse. Daar is tans geen geregistreerde mikoplasma entstof beskikbaar vir gebruik in volstruise nie. Hierdie studie het die ontwikkeling van DNS-entstowwe teen Ms03-infeksies in volstruise ondersoek. Vir hierdie doel was die Ms03-genoomvolgorde bepaal en geannoteer. Die entstofkandidaat-geen, oppA, was geïdentifiseer in die genoomvolgorde en gekarakteriseer voordat DNS-entstowwe (wat die oppA-geen bevat) ontwikkel en getoets is. Die Ms03-genoomvolgorde was bepaal en die gegenereerde 172 aaneenlopende volgordes was geannoteer. Hierdie proefskrif bied die eerste voorlopige volgorde en annotering van die Ms03-genoom wat bygedra het tot die kennis van Ms03 as 'n miniatuur geneties onafhanklike organisme. Genoom-replikasie, seldeling, RNS-transkripsie, proteïen-translasie en glikolise in Ms03 stem ooreen met dié prosesse in die naverwante Mycoplasma synoviae 53. Die purien en pirimidien metabolisme was onvolledig en de novo sintese daarvan was nie moontlik in Ms03 nie. Aminosuursintese in Ms03 was meestal afwesig en net die gene wat aspartaat omskep na asparagien en glisien na serien was gevind in die annoteerde genoom. Meer invoerders as uitvoerders was geannoteer, wat dui op die gebrek aan sintesepadweë in Ms03. Dit is tipies van mikoplasmas wat ‘n parasitiese lewensstyle het. Twee oligopeptied-permeases (opp) operons was gevind in die Ms03-genoom. Die potensiaal van die oppA-geen as 'n entstofkandidaat-geen was geëvalueer deur die behoefte van 'n substraatbindingsdomein (OppA) as deel van die OppBCDF-vervoerder binne mikoplasma spesies te ondersoek. 'n Homoloog van die oppA-geen kon geïdentifiseer word vir elke oppBCDF-operon in al die spesies en behoort daarom 'n noodsaaklike rol te speel in die vervoer van oligopeptiede. Alle mikoplasmas (behalwe vir hemoplasmas) het een, twee of drie opp-operons, wat verdeel kan word in drie tipes (Tipe A, B en C). Elke tipe het unieke InterPro en MEME domeine en motiewe wat saam met die filogenetiese ontleding daarop dui dat hulle unieke rolle in oorlewing onder verskillende omstandighede speel. Ms03 het 'n Tipe A en Tipe B opp-operon, die Tipe A oppA is gebruik as entstofkandidaat-geen. Die Tipe A oppA-geen was gekloneer en teikengerigte-mutagenese was gebruik vir kodonregstellings voordat die gemuteerde geen in drie DNS-entstof vektore gesubkloneer was. Die drie DNS-entstowwe (pCI-neo_oppA, VR1012_oppA en VR1020_oppA) was gebruik om volstruise in te ent en die OppA-teenliggaamsreaksie was geanaliseer deur ELISA. Inenting met die VR1020_oppA en pCI-neo_oppA entstowwe het tot 'n primêre immuniteitsreaksie in volstruise gelei. Dit dui daarop dat die OppA proteïen in vivo uitgedruk en immunogenies was. Dit kan beskou word as die eerste stap in die ontwikkeling van 'n DNS-entstof vir die beheer van mikoplasma-infeksies in volstruise.

>Magister Scientiae - MSc
Campylobacter and related Epsilonproteobacteria (Arcobacter and Helicobacter) are currently viewed as emerging pathogens and are able to cause gastroenteritis, bacteraemia, the Guillain-Barré syndrome, reactive arthritis and other diseases in humans. While poultry, cattle and sheep are known reservoirs for campylobacter, very little is known about ostriches as a vector for these organisms. What is known, however, is that these birds can and sometimes do get infected. Studies by various researchers have provided evidence that various species of animals shed Epsilonproteobacteria in their faeces. In this study, qualitative microbiological assays were performed on liver, caecum and colon samples predominantly from healthy ostriches presented for slaughter, to detect any Epsilonproteobacteria present. Samples were collected at an abattoir in the Western Cape between February and December 2010. Qualitative microbiological assays were also performed on 50 faecal samples collected on a farm. Epsilonproteobacteria were isolated from the tissue samples and characterized following the phenotypic and biochemical scheme presented in the Cape Town protocol. This protocol uses membrane filtration onto antibiotic-free Tryptose blood agar plates, and incubation at 37 ºC in a hydrogen-enhanced microaerobic atmosphere (Lastovica, 2006). The isolates were identified as C. jejuni subsp. jejuni. The multiplex PCR of Neubauer and Hess (2006) was applied to some of these isolates. A panel of isolates consisting of C. jejuni subsp. jejuni, C. fetus and E. coli was used to verify the DNA extraction procedure. The C. fetus and E. coli isolates were used as negative controls, and although DNA was successfully extracted from them, no bands were observed in the respective lanes of electrophoresed gels after application of the PCR.

Thesis (PhD(Agric))--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The ostrich industry experiences high rates of embryonic mortalities during artificial incubation of eggs. Studies have been carried out to investigate factors influencing hatchability, as well as determining genotypic effects for commercial production. Eggs from the combination of South African Black (SAB) male ostriches crossed with Zimbabwean Blue (ZB) female ostriches had embryonic losses of 45.7%. The embryonic mortality of eggs produced by pure bred SAB or ZB breeding birds subjected to pure breeding was similar at around 33 - 34%, but embryonic mortality was improved in eggs produced by ZB males and SAB female crosses (27%). Female age had a significant effect on the proportion of chicks pipped, as well as on early and late the embryonic mortalities. Chicks from eggs stored for intermediate periods, i.e. 3, 4 and 6 days prior to being set, were more likely to pip than chicks from those eggs set directly after collection without storage. Embryonic mortality was increased in eggs that were set directly (32.0%) or subjected to longer than 6 days of storage (43.5%). Chicks that pipped in the correct position had a higher probability of successfully hatching than those pipping in the incorrect position. Transfer of eggs between setters (i.e. disturbance of eggs) during incubation reduced the number of ostrich chicks pipping in the correct position. Incubated ostrich eggs with intermediate levels of water loss, i.e. between 9.0 and 19% of fresh egg weight, were more likely to pip in the correct position than those with higher or lower levels of water loss. Such eggs were also less likely to sustain early, late or overall embryonic mortalities. To optimise hatching success it is important to understand embryonic development. After 2 days of incubation the blastoderm area in eggs from the SAB x ZB crosses (104.5 mm) was lower (P < 0.05) compared to the pure SAB (141.0 mm), pure ZB (161.7 mm) and ZB x SAB crosses (166.1 mm). For embryos incubated for 7 to 42 days, both embryonic and leg growth during the 42 days of incubation was similar and approximately linear, more or less doubling in size up to 35 days of incubation. The embryo eye size increased more rapidly than beak length and reached full size of approximately 16.2 mm by 28 days of incubation, whereas the beak length continued to increase until the chick hatched at 42 days. Incubation position, vertical or horizontal, did not affect any of the measurements of the developing embryo throughout the 42-day incubation period. Air cell volume at 29 day of incubation for infertile eggs (19.3%) was significantly (P < 0.05) higher when compared to dead-in-shell eggs (14.3%) and eggs that hatched successfully (13.8%). Air cell volume was largely independent of strain (SAB or ZB) and whether chicks were assisted to hatch or not. After 41 days of incubation there was a significantly greater (P < 0.05) air cell volume in eggs that hatched normally compared to dead-in-shell eggs (28.3% vs. 21.7%, respectively, suggesting that insufficient water loss contributed to reduced survival. This study provides an insight into the complexity of embryo development and all the factors playing a role in successful hatching of ostrich eggs. Data from a pair-mated ostrich flock were used to estimate genetic parameters for egg weight (EWT), weight of day-old chicks (CWT), water loss to 21 (WL21) and 35 (WL35) days of incubation, and pipping time (PT). Single-trait estimates of heritability (h2) were high and significant (P < 0.05) at 0.46 for EWT, 0.34 for CWT, 0.34 for WL21, 0.27 for WL35 and 0.16 for pipping time. Genetic correlations with EWT amounted to -0.21 for WL21 and to -0.12 for WL35. Corresponding correlations of CWT with WL were highly significant (P < 0.05) at -0.43 and -0.54. Physical characteristics of the eggshell were found to affect water loss and hatchability. Estimates of genetic parameters of 14 146 ostrich eggs for eggshell traits showed that heritability was 0.42 for pore count (PC), 0.33 for shell thickness (ST) and 0.22 for permeability (PERM). PC was negatively correlated with average pore diameter (-0.58) and ST (-0.23), while PC was positively correlated with total pore area (0.58), WL21 (0.24) and WL35 (0.34). The correlations of PC with total pore area and PERM were high and significant. ST was negatively correlated to WL21 and WL35. Additive genetic parameters strongly indicate that it should be possible to alter evaporative water loss and eggshell quality of ostrich eggs through genetic selection. When assessed as a trait of the individual egg or chick, embryonic mortalities exhibited moderate levels of genetic variation both on the normal scale (h2 = 0.16 - 0.22) and the underlying liability scale (h2 = 0.21 - 0.31). Early embryonic survival and late embryonic survival was governed mostly by the same genes (rg = 0.78). Late embryonic survival was genetically correlated to WL35, at -0.22. It was concluded that embryonic survival could be improved by using husbandry measures, a knowledge of the stage when incubation mortalities occur, and by genetic selection, using an integrated approach. Findings from this study will help to understand the mechanisms involved in hatching from artificial incubation better to improve hatchability and also implement selective breeding programs.
AFRIKAANSE OPSOMMING: Die volstruisbedryf ondervind tans ‘n baie hoë voorkoms van embrionale mortaliteite tydens die kunsmatige uitbroei van eiers. Studies is uitgevoer om die faktore wat uitbroeibaarheid beinvloed te ondersoek en om genotipiese effekte te bepaal vir kommersiële produsente. Eiers van die kombinasie van Suid-Afrikaanse swart (SAB) mannetjie volstruise, met Zimbabwean blou (ZB) wyfies, het embrionale mortaliteite van 45.7% gehad. Embrionale mortaliteite van eiers gelê deur suiwer SAB of ZB volstruise was dieselfde op omtrent 33 - 34%, maar embrionale mortaliteite was laer vir eiers geproduseer deur SAB wyfies wat gekruis was met ZB mannetjies (27%). Wyfie ouderdom het ‘n betekenisvolle effek gehad op die proporsie van kuikens wat gepik het, asook die aantal vroeë- en laat embrionale mortaliteite. Kuikens vanuit eiers wat vir die periode 3, 4 dae en 6 dae voor pak in die broeikaste gestoor is, was meer geneig om te pik as kuikens vanaf eiers wat direk na kolleksie gepak is. Embrionale mortalitiete het verhoog vir eiers wat direk na kolleksie gepak was (32.0%) of vir eiers wat langer as 6 dae gestoor was (43.5%). Kuikens wat in die korrekte posisie pik het ‘n hoër kans op uitbroei gehad as kuikens wat in die verkeerde posisie gepik het. Die skuif van eiers tussen verskillende broeikaste (of enige steurnisse) gedurende die broeiproses het ‘n verlaging in die aantal kuikens wat in die korrekte posisie pik, gehad. Volstruiseiers met ‘n gemiddelde vogverlies van tussen 9.0 en 19% van die vars eier massa, was meer geneig om in die korrekte posisie te pik as eiers met laer of hoër vlakke van vogverlies. Sulke eiers was ook minder geneig tot vroeë, laat en totale embrionale mortaliteite. Vir optimale uitbroeisukses is dit belangrik om die ontwikkeling van die embrio te verstaan. Na 2 dae van broei was die blastoderm area in eiers van SAB x ZB kruisings (104.5 mm) kleiner (P < 0.05) as die blastoderm area van suiwer SAB (141.0 mm), suiwer ZB (161.7 mm) en ZB x SAB kruise (166.1 mm). Beide embrionale- en beengroei tydens die 42 dae broeiproses was dieselfde en nagenoeg lineêr, met ‘n verdubbeling in grootte tot en met 35 dae broei. Die embrio se oog vergroot vinniger as wat die snawel verleng en bereik reeds volle grootte van ongeveer 16.2 mm op 28 dae van broei, terwyl die snawel aanhou groei tot uitbroei van die kuiken op 42 dae. Nie die vertikale of horisontale broeiposisie het enige invloed op die metings van die ontwikkelende embrio tot op 42 dae gehad nie. Lugsakvolume vir geil eiers (19.3%) op 29 dae van broei was groter (P < 0.05) as beide die lugsakke van eiers wat dood-in-dop (14.3%) en eiers wat suksesvol uitgebroei het (13.8%). Die lugsakvolume was onafhanklik van beide genotype en of die kuiken met of sonder hulp uitgebroei het. Na 41 dae broei was lugsakvolume groter (P < 0.05) vir eiers wat uitgebroei het teenoor eiers wat dood-in-dop was (28.3% vs. 21.7%, onderskeidelik), wat impliseer dat onvoldoende vogverlies moontlik kan bydrae tot ‘n verlaging in embrionale oorlewing. Hierdie studie gee ‘n insig in die kompleksiteit van embrionale ontwikkeling en al die faktore wat ‘n rol speel in die suksesvolle uitbroei van volstruiseiers. Tydens die bepaling van genetiese parameters vir spesifieke uitbroei-eienskappe in volstruise, is data gebruik afkomend van ‘n teelkudde in ‘n enkelparing stelsel om genetiese waardes vir eiermassa (EWT), dagoud kuikenmassa (CWT), vogverlies tot 21 dae broei (WL21), vogverlies tot 35 dae broei (WL35) en piktyd (PT) gebruik. Enkeleienskap-beraming vir oorerflikheid (h2) was hoog en betekenisvol teen 0.46 vir EWT, 0.34 vir CWT, 0.34 vir WL21, 0.27 vir WL35 en 0.16 vir piktyd. Genetiese korrelasies met EWT was -0.21 vir WL21 en -0.12 vir WL35. Ooreenkomstig was korrelasies van CWT met WL21 en WL35 hoog (P < 0.05) met -0.43 en -0.54 onderskeidelik. Fisiese eienskappe van die eiers het beide vogverlies en uitbroeibaarheid beinvloed. Beramings van genetiese parameters vir 14 146 volstruiseiers se dopeienskappe het gewys dat oorerflikehid 0.42 was vir die aantal porieë (PC), 0.33 vir dopdikte (ST) en 0.22 vir deurlaatbaarheid (PERM). PC was negatief gekorreleerd met gemiddelde porieë deursnee (-0.58) en ST (-0.23), terwyl PC positief gekorreleerd was met totale porieë area (0.58), WL21 (0.24) en WL35 (0.34). Die korrelasie van PC met totale porieë area en deurlaatbaarheid was hoog en betekenisvol. ST was negatief gekorreleerd met WL21 en WL35. Additiewe genetiese parameters het sterk daarop gedui dat dit moontlik sou wees om vogverlies en eierkwaliteit (bv. dopkwaliteit en poreusiteit) van volstruiseiers te verander deur genetiese seleksie. Indien embrionale mortaliteit geevalueer word as ‘n kenmerk van die eier of kuiken, toon dit matige vlakke van genetiese variasie op beide die normale (h2 = 0.16 - 0.22) en die onderliggende skale (h2 = 0.21 - 0.31). Beide vroeë- en laat embrionale oorlewing word deur dieselfde stel gene beheer (rg = 0.78). Laat embrionale oorlewing was geneties gekorreleerd met WL35 teen -0.22. Die gevolgtrekking was dat embrionale oorlewing verbeter kan word deur verbeterde broeikamerpraktyke, kennis van op watter stadium van ontwikkelings embrionale mortaliteite plaasvind en deur genetiese seleksie. Bevindinge vanuit hierdie studies sal help om die meganismes betrokke by die kunsmatige uitbroei van volstruiskuikens beter te verstaan om sodoende uitbroeibaarheid te verbeter en ook suksesvolle seleksie programme te implementeer.

The study includes separate papers, which are all linked by their emphasis on the effect of different diets on the impact of the development of the small intestine of the young ostrich. This abstract is intended to provide readers with a broad overview of the outcomes of the study. Part 1: Yolk utilisation and the development of the small intestines Chapter 2 deals with the composition of egg yolk as it is absorbed by starved ostrich Struthio camelus L. ) chicks from one to seven days post-hatching and for ostrich (Struthio camelus L.) chicks from one to sixteen days post-hatching on a pre-starter broiler diet. Chapter 3 provides information on the intestinal enzymes of ostrich (Struthio camelus L. ) chicks from one to sixteen days post-hatching on a pre-starter broiler diet. The effect of growth on enzyme activity immediately post-hatching up to sixteen days of age was studied. Chapter 4 details a histological and morphological study of the gastrointestinal tract of ostrich (Struthio camelus L.) chicks from two to sixteen days post-hatching on a pre-starter broiler diet. The effect of growth on histological and morphological changes in the various parts of the small intestines was examined. Part 2: Influence on various pre-starter diets on growth and the development of the intestinal tract Chapter 5 discussed a growth and digestibility study of ostrich (Struthio camelus L.) chicks on eight different pre-starter diets. The performance, growth and physiological development of the chicks on high and low variations of different nutritional components were examined. Chapter 6 provides information on certain intestinal enzymes of ostrich (Struthio camelus L.) chicks on the eight different pre-starter diets. Chapter 7 dealt with the histological and morphological changes of the gastrointestinal tract of ostrich (Struthio camelus L.) chicks as a result of high and low variations of different nutritional components in prestarter diets. Implications The first part of this study revealed that although it appeared that yolk content was absorbed faster in starved ostrich chicks, intake of external feed had a positive influence on the absorption of fat from the yolk. The changes in the fatty acid composition of the yolk fat content that were observed may indicate that ostrich chicks have the ability to withdraw certain fatty acid components, especially unsaturated fatty acids. The digestive tract of ostrich chicks was compared with that of broiler chicks and differences observed in amylase and lipase activity between the birds in this trial and in poultry could be due to genetic differences between species. It could also be due to the genetic homogeneity of the poultry chicks that were used in the trials, whereas ostrich chicks have not been subjected to the same extent of advanced breeding improvement to date. Results on histological and morphological growth of the small intestines of the ostrich chick indicate increased absorption with an increase in age. The second part of this study revealed that ostrich chicks performed differently on diets formulated with different nutritional components. It appears that a high fat and low sugar content in the diet is advantageous in ostrich pre-starter diets. Although there were a few mortalities during the trials, there is no clear indication as to why the chicks died, as the causes of mortalities were not investigated. Differences in composition of the eight pre-starter diets did not seem to have an influence on the protein content or enzyme activity of the small intestines of ostrich chicks. An anti-nutritional factor within certain feedstuffs may, however, have had an influence on enzyme activity. Similar results were obtained for the histological and morphological parameters which were measured in chicks fed the different diets. There was no single diet that promoted intestine development, although it seemed as if the small intestines of the chicks fed the high protein diet were under higher digestive stress than those of the chicks fed the other diets.
Thesis (PhD)--University of Pretoria, 2011.
Anatomy and Physiology
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Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2006.
The aim of this study is to determine the effect of crossbreeding Zimbabwean Blue (ZB) and South African Black (SAB) ostriches on the morphological, physical, chemical and sensory quality of the meat. However, it is also necessary to determine the reproductive performance of these genotypes to scientifically support decisions made in the ostrich industry. In relation to reproductive traits and body measurements influencing these traits, results from the study suggested that ZB birds are between 9 and 15% heavier than their SAB contemporaries. Regarding SAB females, egg production was 47% higher, levels of shell deaths were lower, percentage of eggs not incubated was lower (P<0.01) and 84% more (P<0.01) chicks were produced in a season compared to their ZB contemporaries. Mates of SAB males produced a higher (P≤0.05) percentage of eggs not incubated and higher shell death percentages than the mates of ZB males. It has to be conceded that ZB females had a lower reproduction than SAB females, limiting the application of this genotype as a dam line in crossbreeding systems. With regard to morphological properties, the pure Blue genotype in comparison to the pure Black genotype differed significantly (P≤0.05), with 16 kg for live weight, 8.3 kg for carcass weight and 3.5 kg for leg weight. However, when comparing carcass yields (expressed as %) there were no significant differences (P>0.05) between genotypes. The M. gastrocnemius, M. femorotibialis accessorius, M. iliotibialis cranialis, M iliotibialis lateralis, M. iliofibularis and M. iliofemoralis showed significant genotype differences (P≤0.05) for individual muscle weight. When comparing the physical meat quality characteristics between the pure Blue genotype and the pure Black genotype, 70% of the muscles were higher (P≤0.05) in pH24, 50% of the muscles were redder (P≤0.05) and significantly less (P≤0.05) saturated in colour, 67% of the muscles had a lower (P≤0.05) percentage drip loss and 50% of the muscles had a lower (P≤0.05) percentage cooking loss. No significant (P>0.05) genotype differences were observed regarding the sensory quality of the meat. Regarding chemical meat quality characteristics, the percentage of moisture was higher and the percentage of lipid was lower for eight of the ten muscle groups from the pure Blue genotype. No significant differences (P>0.05) were found between genotypes or between muscles regarding the percentage of protein present in the meat. The highest (P>0.05) content of soluble collagen, myoglobin and cholesterol was found in the Blue x Black genotype, whereas the lowest percentage of the latter constituents was found in the pure Blue genotype. For the pure Black genotype the concentration of saturated fatty acids in the meat was lower (P≤0.05), the concentrations of total unsaturated fatty acids and desirable fatty acids in the M. illiofibularis were the highest (P≤0.05), while the concentration of monounsaturated fatty acids was also higher (P≤0.05) in both muscles of this genotype compared to the other two genotypes. Regarding both fat depots, the pure Black genotype had a lower (P≤0.05) concentration of saturated fatty acids, a higher (P≤0.05) concentration of monounsaturated fatty acids and total unsaturated fatty acids and a higher (P≤0.05) polyunsaturated:saturated fatty acid ratio. The percentage of desirable fatty acids in the abdominal fat depot was significantly higher (P≤0.05) for the pure Black and the Blue x Black genotype. In conclusion, crossbreeding between SAB and ZB ostriches seems to be a viable option to produce larger birds with more meat, without negatively affecting the overall quality of the meat.

Thesis (MScVoedselwet)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Two experiments were conducted in order to manipulate the physical and chemical properties and shelf life of ostrich meat. Experiment 1: The effect of dietary fish oil rich in n-3 fatty acids on the organoleptic, fatty acid and physicochemical characteristics of ostrich meat. The diet of four ostrich groups (15 birds per group), approximately 3 months of age (ca. 41 kg live weight) grazing a predominantly oats pasture, was supplemented with a diet containing 6.7% fish oil. The birds received a supplement of either 0 (diet 1), 800 (diet 2), 1600 (diet 3) or 2400 g (diet 4) DM/day resulting in the consumption of 0 (diet 1), 14.5 (diet 2), 29 (diet 3) and 43.5 (diet 4) g fish oil per day. The ostriches were slaughtered at 10 months of age (ca. 70 kg live weight). An increase in the amount of fish oil consumed was found to have had statistically no significant effect on the sensory characteristics of the M. iliofibularis, although there was a tendency towards an increase in ‘fishiness’, for both aroma and flavour. However, increased concentrations of fish oil had a significant effect on the aroma and flavour of the abdominal fat pads. The muscle pHf and muscle lightness (L*) reflected a significant reduction with increased fish oil levels. The increased feed intake, on the other hand, had no effect on the chemical composition (moisture, protein, fat and ash content) of the meat. The fatty acid profile of both fat and meat was affected by the consumption of fish oil. The SFA concentration increased, while the PUFA concentration decreased, with an increase in feed intake. The MUFA concentration remained constant for all four groups. Experiment 2: The effect of dietary vitamin E and the type of packaging on the sensory quality, physicochemical composition and shelf life of ostrich meat. Two groups of ostriches (35 birds per group; ca. 3 months old) were fed diets containing either 40 mg/kg feed vitamin E (control) or 150 mg/kg feed Vitamin E for nine months. The birds were slaughtered at 12 months of age. The effect of different the levels of vitamin E and heat shrink treatment of vacuum packaging material on the shelf life of refrigerated (0°C) ostrich M. flexor cruris lateralis, was evaluated over 81 days. Vitamin E and heat shrink treatments were found to have had no significant effect on the sensory characteristics; off-meat aroma, sourness, juiciness and mealiness. Rancidity was found to be slightly more pronounced (although not statistical significant) in the vitamin E and heat shrink groups than in the feed control and vacuum-packed groups. A significant decrease in the organoleptic quality of the meat, over a 40 day shelf life period, was observed. The pH and muscle tenderness showed a significant reduction with increased storage time. The purge loss in the package increased over time with no change in muscle drip loss. The colour, conjugated dienoic acid and fatty acid content showed no significant changes over time or with regards to treatment. The total viable counts and coliform numbers in the muscle increased over time, with the coliforms being slightly suppressed by the inclusion of vitamin E in the diet. A microbiological safe shelf life of 40 days at 0°C was obtained.
AFRIKAANSE OPSOMMING: Twee eksperimente is uitgevoer om die fisiese en chemiese eienskappe, asook die rakleeftyd van volstruisvleis, te manipuleer. Eksperiment 1: Die effek van visolie, ryk aan n-3 vetsure, op die organoleptiese, vetsuur- en fisies-chemiese eienskappe van volstruisvleis. Die dieet van vier groepe volstruise (15 voëls per groep), ongeveer 3 maande oud (ca. 41 kg lewende massa) wat ‘n hawer weiding bewei het, is aangevul met ‘n byvoedingsmengsel wat 6.7% visolie bevat en in toenemende hoeveelhede vir die groepe volstruise gevoer is. Die voëls het ‘n aanvulling van 0 (dieet 1), 800 (dieet 2), 1600 (dieet 3) of 2400 g (dieet 4) DM/dag ontvang wat gelei het tot ‘n inname van 0 (dieet 1), 14.5 (dieet 2), 29 (dieet 3) en 43.5 (dieet 4) g visolie per dag. Die volstruise is op ‘n ouderdom van 10 maande geslag (ca. 70 kg lewende massa). ‘n Toename in die hoeveelheid visolie ingeneem, het geen statisties betekenisvolle effek op die sensoriese eienskappe van die M. ilifibularis gehad nie, alhoewel daar ‘n tendens was vir ‘n toename tot ‘n ‘visagtige’ aroma en smaak. ‘n Toename in die konsentrasie visolie het egter ‘n betekenisvolle effek op die ‘visagtige’ aroma en smaak van die abdominale vet neerslae gehad. Die spier pHf en spier ligtheid (L*) het ‘n betekenisvolle afname met toename in voer inname getoon. Die verhoogde olie inname het egter geen effek op die chemiese samestelling (vog-, proteïen-, vet- en asinhoud) van die vleis gehad nie. Die vetsuurprofiel van beide die abdominale vet neerslae en die vleis is deur die inname van visolie verander. Die versadigde vetsuurkonsentrasie het verhoog terwyl die poli-onversadigde vetsuurkonsentrasie verlaag het met ‘n toename in rantsoenvlakke. Die mono-onversadigde vetsuurkonsentrasie het egter konstant gebly vir al vier groepe. Eksperiment 2: Die effek van vitamien E en die tipe verpakking op die sensoriese kwaliteit, fisies-chemiese samestelling en rakleeftyd van volstruisvleis. Twee groepe volstruise (35 voëls per groep, ongeveer 3 maande oud) het voere oor ‘n tydperk van nege maande ontvang wat 40 mg vitamien E/kg voer (kontrole) of 150 mg vitamien E/kg voer bevat het. Die voëls is op 12 maande ouderdom geslag. Die effek van die verskillende vlakke van vitamien E en hitte-behandeling van die verpakkings materiaal op die rakleeftyd van verkoelde (0°C) volstruis M. flexor cruris lateralis, is oor 81 dae geëvalueer. Vitamien E en die hitte-behandeling het geen betekenisvolle effek op die organoleptiese eienskappe (af-vleis aroma, suurheid, sappigheid en melerigheid) gehad nie. Galsterigheid was ‘n bietjie meer gedefinieerd (anie-betekenisvol) in die vitamien E en hitte behandelde groepe as in die rantsoen kontrole en vakuum verpakte vleis. ‘n Betekenisvolle afname is waargeneem in die organoleptiese kwaliteit van die vleis oor ‘n 40 dae rakleeftyd periode. Die pH en taaiheid van die spier het betekenisvol afgeneem met ‘n toename in bergingsperiode. Die drup verlies tydens verpakking het ook oor tyd toegeneem, terwyl geen verandering in die analitiese drup verlies van die spier verkry is nie. Die kleur, gekonjugeerde dieensuur en vetsuursamestelling het geen verandering oor tyd of ten opsigte van behandeling getoon nie. Die Totale Lewendig Seltelling en coliforme het toegeneem oor tyd, terwyl die coliforme deur die byvoeging van vitamien E tot ‘n mate onderdruk is. ‘n Mikrobiologies veilige rakleeftyd van 40 dae is verkry.

Orientador: Márcia Rita Fernandes Machado
Banca: Tiago Luís Eilers Treichel
Banca: José Ribamar Privado Filho
Banca: Paola Castro Moraes
Banca: Fabrício Singaretti de Oliveira
Resumo: Estudou-se a anatomia do timo em 30 filhotes de avestruzes, 13 machos e 17 fêmeas com idade variando entre 10 a 20 dias, mediante fixação de cada ave em solução aquosa de formol a 10%. As cadeias de lobos tímicos localizaram-se no terço distal da região ventral do pescoço, dispondo-se de forma linear e paralela, desde a décima primeira até a décima quinta vértebra cervical, relacionando-se com o nervo vago e veia jugular. O número de lobos variou de 1 a 3 e 1 ou 2, para os antímero direito e esquerdo respectivamente. A média das dimensões dos lobos foram 2,09 x 0,71 x 0,41 cm para o lobo cranial, 0,69 x 0,38 x 0,27 cm para o lobo médio e 0,55 x 0,33 x 0,29 cm para o lobo caudal do antímero direito. No antímero esquerdo foram registrados de 2,14 x 0,71 x 0,37 cm para o lobo cranial e 0,60 x 0,31 x 0,22 cm para o lobo caudal. Os lobos tímicos direitos e esquerdos mostraram-se nutridos, em todos os casos, por vasos oriundos, direta e exclusivamente, das artérias comuns dos nervos vagos, esofágicas ascendentes e cervicais cutâneas ascendentes direitas e esquerdas. Os lobos tímicos do antímero direito receberam, independentemente de sua origem, de um a cinco ramos e do antímero esquerdo, houve uma variação de um a quatro ramos. A morfologia e vascularização arterial do timo apresentaram comportamentos bem definidos, possuindo características comuns que identificam a espécie que foi objeto de nosso estudo
Abstract: It was studied the morphology and the biometry of the thymus in 30 young ostriches, 13 males and 17 females aged from 10 to 20 days, by setting each bird in aqueous solution of 10% formaldehyde. Chains of thymic lobes were located in the third distal part of the ventral neck, offering up linear and parallel, from the eleventh to the fifteenth cervical vertebra, relating to the vagus nerve and jugular vein. The number of lobes varied from 1 to 3 and 1 or 2, to right and left antimeres respectively. The average dimensions of the lobes were 2.09 x 0.71 x 0.41 cm to the cranial lobe, 0.69 x 0.38 x 0.27 cm to the middle lobe and the 55 x 0.33 x 0.29 cm to the caudal lobe of the right side. On left antimere were found the average dimensions of the lobes of 2.14 x 0.71 x 0.37 cm for cranial lobes and 0.60 x 0.31 x 0.22 cm to the caudal lobes. Thymic right and left lobes shown to be nourished, in all cases, for vessels coming directly and exclusively, common arteries of the vagus nerves, skin and cervical esophageal ascending upward right and left . Thymic lobes of the right side received, regardless of its source, from one to five branches and left antimere, there was a variation of one to four branches. The morphology and thymus biometrics showed well-defined behaviors, possessing common characteristic who characterized the specie that was the subject of our study
Doutor

Hoje a criação de avestruz ((Struthio camelus, Linnaeus 1758)) é uma atividade de grande potencial, porém não existem padrões definidos sobre a histologia do seu fígado, que é um órgão de grande importância no metabolismo, o conhecimento de sua histologia e anatomia pode contribuir para a detecção de doenças e deficiências nutricionais que influenciam no crescimento e desenvolvimento do animal. Os objetivos desta pesquisa são: Estudar a anatomia e histologia do fígado e a ramificação de sua artéria hepática, veia porta hepática e ducto biliar. Para a realização da parte macroscópica foram utilizados quinze avestruzes com idades entre 12 e 18 meses (com peso médio em torno de 80 a 100 kg), provenientes do abatedouro Don Pig, situado próximo à cidade de Botucatu no estado de São Paulo. Os animais foram abatidos com pistola pneumática e posteriormente submetidos a sangria. Foram injetadas com látex a artéria hepática, o ducto biliar e a veia porta. O fígado dos avestruzes apresentam dois lobos (direito e esquerdo). No caso o direito é maior que o esquerdo e ambos são subdivididos em dorsal, intermédio e ventral. Além disso, amostras do fígado foram processadas para a observação em microscopia de luz e microscopia eletrônica de transmissão (MET). A hematoxilina e eosina (H.E), picrossírius, Gordon e Sweets, Sudan black e o ácido peródico de Schiff (PAS) são colorações usadas respectivamente para observar a morfologia do fígado, colágeno, fibras reticulares, gordura e glicogênio. Foram encontrados os espaços porta- hepáticos (artéria hepática, veia porta e ducto biliar e as veias centrolobulares). O glicogênio presente mostrou a média de 5,68%. O conteúdo lipídico, conferiu um aspecto goticular compatível com um quadro de esteatose hepática e a média obtida foi de 9,83%. Foi encontrado colágeno ao redor dos espaços porta-hepáticos, artérias centrolobulares e capilares sinusóides e a média foi de 14,71%. Encontrou-se também fibras reticulares ao redor dos capilares sinusóides e a média foi de 5,96%. Quanto à MET notou-se que no citoplasma dos hepatócitos desses animais existem numerosas mitocôndrias, glicogênio, muitas gotas de gordura, alguns lisossomos, retículo endoplasmático granular ao redor das mitocôndrias, algumas células estreladas, eritrócitos, núcleo, célula em degeneração e o canalículo biliar ao centro. Provavelmente o quadro sugestivo de esteatose é resultante do estado nutricional dos animais, já que nenhum outro aspecto relevante foi encontrado. Como estas aves são destinadas ao abate, sua alimentação é formulada para que os animais apresentem rápido desenvolvimento e alto ganho de peso, provavelmente com níveis de lipídios acima do necessário, causando uma deposição de micelas de gordura nos hepatócitos. Estes resultados demontraram que os hepatócitos dos avestruzes são muito simulares as outras aves apesar de também serem muito similares na estrutura das células do fígado de mamíferos.
At present the ostrich (Struthio camelus) breeding has been showing a great economical potential, although yet there are not distinct patterns about the histology of its liver, which is an organ of key importance in terms of metabolism. The knowledge of its histology and anatomy can help the detection of diseases and nutritional deficiencies that affect the growth and development of this bird. The aims of this work are to study the liver anatomical and histological structure and the branching of the hepatic artery, hepatic portal vein and bile duct. In the macroscopic study 15 ostriches with an average age of 12-18 months and average weight of 80-100 Kg, proceeding from Don Pig Abatteur, located next to Botucatu, São Paulo, were used. The birds were slaughtered with air gun and subsequently submitted to bleeding. The hepatic artery, the bile duct and the hepatic portal vein were injected with latex. The ostrich liver presents two lobules (right and left), being the right one larger than the left and both are subdivided into dorsal, intermediate and ventral. Liver samples were processed for light and electron transmission microscopic studies. Hematoxilin and eosin (HE), picrosirius, Gordon and Sweets, Sudan black and Schiff periodic acid (PAS) were respectively used to observe the liver morphology, collagen, reticular fibers, lipids and glycogen. The liver portal spaces were determined (hepatic artery, portal vein, bile duct and centrolobular veins). An average of 5.68% of glycogen was observed. The lipidic content provided a droplet aspect compatible to hepatic esteatosis, with an average of 9.83%. Collagen fibers around the liver portal spaces, centrolobular arteries and sinusoidal cappilaries were detected, at an average of 14.71%, as well as reticular fibers located in the vicinity of sinusoidal capillaries with an average of 5.96%. Through transmission electron microscopy we noticed in the hepaticyte cytoplasm the presence of numerous mithocondria, glycogen, several lipidic droplets, some lysosomes, granular endoplasmatic reticulum around the mithocondria, some stellate cells, erythrocytes, nucleus and degenerating cells, besides the central biliary canaliculus. The suggestive steatotic results might result from the animals nutritional status, once no other relevant aspect was detected. The birds are slaughtered for food comsumption and their ration is balanced striving for faster growth and higher weight gains, which are achieved through extra lipidic levels, motivating deposition of lipidic micelles in the hepatocytes. Our results demonstrated that ostrich and other birds hepatocytes are very similar.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Ostriche breeding has recently achieved commercial importance around the world. It is important to know the parasites those affect animals in commercial farms, as infections can reduce the weight gain, compromise reproductive potential and lead animals to death. Brazil has great environmental differences among its regions, depending on weather conditions and production management, and arrangements must be provided as ostriches are not used to deal with these conditions. The aim of this study was to identify gastrointestinal parasites and checks its seasonal occurrence among animals in a commercial farm in Areal / RJ. Fresh fecal samples were monthly collected (from April/2004 to May/2006) and placed in indentified plastic bags under refrigeration until processing. Centrifugal flotation in sugar saturated solution (counting eggs per grams of feces EPG), faecal culture (identify third-stage - L3 larvae) and centrifugal-sedimentation (protozoa identification) techniques were performed. Two hundred and sixty-four fecal samples were collected and divided in three groups according to ostriches ages: <90, 91 365 and >365 days (adults). Dry and rainy seasons were defined according to meteorological data obtained. Typical eggs of the Order Strongylida were identified in 169 samples (158 from adult ostriches). Once obtained, L3 larvae were identified as Codiostomum struthionis. Species of protozoa were detected in 252 of 264 samples (single and mixed infection). At least one of the three Genus (Cryptosporidium, Blastocystis and Entamoeba) was identified in 95.45% of the samples evaluated. Ostriches >365 days had greater eggs removal during the rainy season compared to dry season, being this difference significant (p=0.0002). When evaluating seasonality, Blastocystis cysts were mostly found among dry season samples (p=0.0043) in the age group of < 90. In the age group > 365 days there was difference significant of removal oocysts/cysts between the dry and rainy seasons for Cryptosporidium (p=0.0161) and Entamoeba (p=0.0387), being higher in the rainy season. Among age group, significant difference of removal of cysts between < 90 and > 365 days to Entamoeba (p=0.0430), greater removal in adults. Significant differences were also found between ages related to EPG disposal (p<0.05 for ostriches < 90 and > 365 days; p<0.05 for ostriches from 91 to 365 and > 365 days), as result of high EPG of adults.
Como o n?mero de criat?rios vem aumentando em todo o mundo, o conhecimento dos parasitos que acometem as avestruzes ? importante, pois quando infectadas pode ocorrer um menor ganho de peso, comprometer o potencial reprodutivo e at? causar a morte. O ambiente brasileiro varia bastante e, dependendo das condi??es clim?ticas de cada regi?o, a efici?ncia de produ??o tamb?m se altera, pois a avestruz ? pouco afeita a ambientes chuvosos. Este trabalho teve como objetivos identificar os parasitos gastrintestinais de avestruzes de uma cria??o em Areal/RJ e verificar a sazonalidade de ocorr?ncia dos parasitos de acordo com a faixa et?ria das aves. Foram coletadas, mensalmente, amostras fecais rec?m emitidas e acondicionadas em sacos pl?sticos devidamente identificados, e mantidas sob refrigera??o at? o momento de serem examinadas. Uma parte das fezes foi processada seguindo a t?cnica de centr?fugo-flutua??o em solu??o saturada de a??car para a contagem de ovos por grama de fezes (OPG). Outra parte foi utilizada na realiza??o de coproculturas para identificar a larva de terceiro est?dio (L3). E a terceira por??o do material fecal foi processada seguindo a t?cnica de centr?fugo-sedimenta??o para identifica??o de protozo?rios. Foram coletadas, entre abril de 2004 e maio de 2006, 264 amostras de fezes de avestruzes divididas em tr?s faixas et?rias: at? 90 dias, de 91-365 dias e acima de 365 dias (adultos). Foram obtidos dados meteorol?gicos para defini??o das esta??es seca e chuvosa. Verificaram-se 170 amostras positivas para ovos t?picos da ordem Strongylida, sendo 159 amostras provenientes de avestruzes adultas. Ap?s a obten??o das L3, estas foram identificadas como Codiostomum struthionis. Foram observados protozo?rios em 252 das 264 amostras examinadas ocorrendo infec??o simples ou mista, ou seja, 95,4% das amostras estavam positivas para pelo menos um dos tr?s g?neros encontrados: Cryptosporidium, Blastocystis e Entamoeba. Ap?s a an?lise estat?stica pode-se observar que na faixa et?ria acima de 365 dias houve diferen?a significativa para libera??o de ovos e entre as esta??es seca e chuvosa (p= 0,0002), sendo a maior elimina??o na esta??o chuvosa. Na an?lise da diferen?a entre as esta??es para protozo?rios houve diferen?a significativa na elimina??o de cisto de Blastocystis (p= 0,0043) na faixa et?ria de 0-90 dias, onde na esta??o seca a libera??o foi maior, e na faixa et?ria acima de 365 dias houve diferen?a significativa de elimina??o de oocistos/cistos entre a esta??o seca e chuvosa para Cryptosporidium (p= 0,0161) e Entamoeba (p= 0,0387), sendo maior na chuva. Entre as faixas et?rias, houve diferen?a significativa de elimina??o de cistos entre 0-90 dias e acima de 365 dias para Entamoeba (p= 0,0430). Para a compara??o de elimina??o de OPG entre as faixas et?rias houve diferen?a significativa entre 0-90 dias e acima de 365 dias (p<0,05) e 91-365 dias e acima de 365 dias (p<0,05), sendo a maior elimina??o nos adultos.

Avian influenza (AI) control in farmed ostriches relies on rapid and accurate diagnostic testing to detect the presence and spread of disease in avian populations, as flocks are in unavoidable contact with wild bird reservoirs, increasing the possibility of infection. Increasing swab pools from five to ten would significantly decrease the cost of testing by reducing the number of tests performed; however detection of highly pathogenic avian influenza (HPAI) at low virus titres by RT-qPCR and virus isolation is critical to ensure that the disease is detected and accurately characterised. The present study found that pooling a single HPAI positive ostrich swab with four or nine AI negative ostrich tracheal swabs did not significantly affect the detection of influenza A virus by RT-qPCR (p < 0.05) over the dilution range. RT-qPCR had a high sensitivity detecting up to 102.5 EID50/ ml (~ RT-qPCR Ct value = 35) virus titre compared to virus isolation, that detected only up 104.8 EID50/ml (~ RT-qPCR Ct value = 29) virus titre, confirming that weak positive swab pools with a low virus titre detected by RT-qPCR (Ct value ≥ 35) may not be detected by standard virus isolation techniques. Both virus transport media evaluated (10% v/v glycerol in brain heart infusion (BHI) broth supplemented with antibiotics (VTM) and 50% v/v glycerol PBS transport medium (pH 7.2)) facilitated the isolation of influenza A virus at ~ 104.5 EID50/ml (RT-qPCR Ct value ~ 27); however VTM improved the efficiency of the method, potentially reducing the reporting time. Sampling costs can be reduced by increasing swabs pools to ten and efficacy of virus isolation can be improved by using antibiotic supplemented VTM, without compromising the detection of influenza A virus by RT-qPCR. It is recommended that costs and efforts are focused at isolating virus from pooled swab samples, with a virus titre of ≥ 104 EID50/ ml (RT-qPCR Ct value ≤ 29), followed by full molecular sequencing and characterisation of the viral isolate. Samples with a low virus titre < 104 EID50/ ml (RT-qPCR Ct value > 29) should be characterised by direct sequencing of PCR amplicons or type-specific RT-qPCR assays.
Mini Dissertation (MSc (Tropical Animal Health))--University of Pretoria, 2019.
Veterinary Tropical Diseases
MSc (Tropical Animal Health)
Unrestricted

Objetivou-se com este estudo caracterizar a anatomia do sistema porta renal e verificar sua influência sobre o protocolo anestésico xilazina, tiletamina e zolazepam na contenção de avestruzes, por comparação da administração dos fármacos nos músculos da perna ou da asa. Para o estudo anatômico, foi injetado, em cinco animais, látex nas veias femorais no sentido de drenagem e posteriormente as aves foram fixadas em formol a 10%, por 72 horas. Em uma ave procedeu-se à localização, colheita e fixação das valvas portais renais em formol a 10%. Os exemplares foram dissecados e o sistema porta renal apresentou-se constituído por duas veias portais renais craniais bem reduzidas, duas veias portais renais caudais e seis valvas portais renais. A veia porta renal caudal apresentou-se relacionada, cranialmente, com a veia femoral, a partir da sua união com a veia ilíaca externa, e caudalmente, com a veia isquiática e ilíaca interna. Na contenção química, utilizaram-se seis avestruzes distribuídos aleatoriamente em dois grupos. O grupo I (GI) recebeu o protocolo nos músculos da base das asas e no grupo II (GII) o protocolo foi administrado nos músculos das pernas. O protocolo anestésico aplicado nos animais dos grupos constou de xilazina (1,0 mg/kg) e após 10 minutos administrou-se a tiletamina/zolazepam (6,0 mg/kg). Foram utilizados os mesmos animais nos dois grupos, respeitando-se um intervalo mínimo de 15 dias entre cada anestesia. O período de latência foi de 5,63±3,9 (GI) e 3,80±2,07 (GII) minutos (p>0,05) após a administração da tiletemina/zolazepam. A qualidade da indução foi razoável e ruim em uma ave (16,67%) do GI e GII, respectivamente. O período hábil anestésico foi de 35,17±8,13 (GI) e 27,33±9,75 (GII) minutos (p>0,05). A freqüência cardíaca permaneceu abaixo dos valores basais durante a anestesia (p<0,05) nos dois grupos. O calor e elevada umidade do ar promoveram aumento da temperatura cloacal nos grupos, principalmente em GII, levando ao incremento da freqüência respiratória para facilitar a perda de calor. O relaxamento muscular foi intenso por 20 minutos em dois animais (33,33%) do GI e por 10 a 15 minutos em cinco aves (83,33%) do GII. O período de recuperação foi de 33,67±10,20 (GI) e 28,83±8,47 (GII) minutos (p>0,05). Nos dois grupos a qualidade de recuperação foi razoável em uma ave (16,67%) e ruim em outro animal (16,67%). A contenção química foi adequada para a realização de procedimentos de curta duração a campo nos avestruzes dos dois grupos, portanto não foi possível evidenciar a influência do sistema porta renal.
The aim of this study was to characterize the anatomy of the renal portal system and to verify its influence on the anesthetic protocol xylazine, tiletamine and zolazepam in the restraint of ostriches, comparing the drugs administration in the muscles of the leg or of the wing. For the anatomical study, it was injected, in five animals, latex in the femoral veins in the drainage direction and afterwards the birds were fixed in formol to 10%, for 72 hours. In a bird it was proceeded to the location, collected and fixation of the renal portal valves in formol to 10%. The animals were dissected and the renal portal system was constituted by two cranial renal portal veins very reduced, two caudal renal portal veins and six renal portal valves. The caudal renal portal vein was related, cranially, with the femoral vein, from its union with the external iliac vein, and caudally, with the ischiatic vein and the internal iliac vein. In the chemical restraint, it was used six ostriches distributed randomly in two groups. Group I (GI) received the protocol in the base muscles of the wings and in group II (GII) the protocol was administered in the muscles of the legs. The anesthetic protocol used in the animals of the groups consisted of xylazine (1,0 mg/kg) and after 10 minutes it was administered tiletamine/zolazepam (6,0 mg/kg). The same animals were used in the two groups, respecting a minimum interval of 15 days between each anesthesia. Latency period was 5,63±3,9 (GI) and 3,80±2,07 (GII) minutes (p>0,05) after the administration of tiletamine/zolazepam. The induction quality was fair and poor in a bird (16,67%) of GI and GII, respectively. The duration of action was 35,17±8,13 (GI) and 27,33±9,75 (GII) minutes (p>0,05). The heart rate remained below the basal values during the anesthesia (p<0,05) in the two groups. The warmth and elevated air humidity promoted cloacal temperature increase in the groups, mostly in GII, leading to the increment of the respiratory rate to facilitate the warmth loss. The muscular relaxation was intense for 20 minutes in two animals (33,33%) of GI and for 10 to 15 minutes in five birds (83,33%) of GII. The recovery period was 33,67±10,20 (GI) and 28,83±8,47 (GII) minutes (p>0,05). In the two groups the recovery quality was fair in a bird (16,67%) and poor in other animal (16,67%). The chemical restraint was adapted for the achievement of procedures of short duration in field in the ostriches of the two groups, therefore it was not possible to evidence the renal portal system influence.

A criação industrial de avestruzes no Brasil tem crescido nos últimos anos, mas avestruzes podem ser reservatórios de agentes com potencial zoonótico, como é o caso do vírus da influenza, rotavírus, vírus da encefalomielite eqüina do leste (EEEV) e do oeste (WEEV), salmonela, leptospira e micoplasma. O objetivo deste trabalho foi detectar rotavírus nas fezes de filhotes, anticorpos contra rotavírus, EEEV e WEEV, influenza A , leptospira, salmonela e micoplasma a partir do soro de reprodutores e efetuar o isolamento de Salmonella sp. a partir de de suabe cloacal. Para a detecção de rotavírus nas fezes utilizaram-se as técnicas de PAGE, isolamento viral e genotipagem pela RT-PCR. As técnicas de contraimunoeletroosmoforese, soroneutralização em cultura de células, inibição da hemaglutinação e aglutinação em placa foram utilizadas nos levantamentos sorológicos e a cultura bacteriológica foi utilizada para detecção de Salmonella spp. em suabes de cloaca. Rotavírus do grupo A com genotipos G[6], G[10], P[1] e P[7] foram detectados nas fezes de avestruzes e anticorpos anti-rotavírus em 10 amostras (10/182) de soros colhidos de avestruzes reprodutores. Foram detectados anticorpos para vários sorovares de Leptospira spp. (19/128), Salmonella pullorum (17/182), Mycoplasma gallisepticum (17/182) e Mycoplasma synoviae (47/182). Não foram detectados anticorpos anti-EEEV e WEEV e anti-vírus da Influenza A H3, bem como amostras de Salmonella spp. em suabes de cloaca. Estes resultados permitem sugerir o papel do avestruz na cadeia epidemiológica das rotaviroses e da leptospirose e dão bases para o aprimoramento sanitário do plantel brasileiro desta ave.
The industrial ostrich breeding in Brazil has grown in the last few years, but ostrich may be reservoirs of potentially zoonotic agents such as influenzavirus, rotavirus, eastern equine encephalitis virus (EEEV), western equine encephalitis virus (WEEV), Salmonella, Leptospira and Mycoplasma. The aim of the present study was to detect rotavirus in fecal samples of young ostriches, antibodies against rotavirus, EEEV and WEEV, influenza A , Leptospira, Sallmonela and Mycoplasma in sera from breeders and carry out Salmonella isolation in cloacal swabs. For the rotavirus detection, PAGE, viral isolation and genotyping by RT-PCR were used. Counterimmunoelectroosmophoresis, virus neutralisation assay in cell culture, hemagglutination inhibition and plate agglutination were used in the serological surveys and bacteriological culture was used to detetc Salmonella spp. in the cloacal swabs. Group A rotavirus with genotypes G[6], G[10], P[1] and P[7] was detected in the fecal samples and anti-rotavirus antibodies were detected in ten samples (10/182) from breeder ostriches. Antibodies to different serovars of Leptospira spp. (19/128), Salmonella pullorum (17/182), Mycoplasma gallisepticum (17/182) and Mycoplasma synoviae (47/182) were detected. Antibodies against EEEV, WEEV and influenzavirus A H3 were not detected, as well as Salmonella spp. in swab samples. These results allow one to suggest a role to ostriches in the epidemiological chain of rotavirus diseases and leptospirosis and give basis to the improvement of the sanitary condition of the Brazilian flocks.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The purpose of this study was to evaluate the production of slaughter ostriches in a grazing environment at different levels of supplementary feed. Two grazing trials were conducted. In the first trial, one group of finisher ostriches (six months old) was put into a feedlot and received a complete finisher diet. The other four groups were allowed to graze lucerne pasture (stocking rate of 15 birds/ha) with 1500, 1000, 500, and 0g supplementary feed/bird/day. Pasture production and intake were measured. There was no difference (P >0.05) between the end mean live weights of the feedlot ostriches and those two grazing groups receiving 1500 or 1000g supplementation. The average daily gain (ADG) of the group receiving 1000g supplementation was lower (P <0.05) than the ADG of the group receiving 1500g supplementation, but all three groups reached a mean target slaughter weight of 95kg within the 154 days of the study. Therefore, pastures together with the correct supplementation (at least 1000g/bird/day) can replace complete feeds in the finishing phase of slaughter ostriches and can play an important role in the production of these birds. For lucerne intake, a quadratic relationship (P <0.01) was found between pasture dry matter (DM) intake (g/bird/day) and supplementary feed intake (g/bird/day). The maximum lucerne intake level (1692.8g/bird/day) was achieved at 619.6g supplementary feed/bird/day. In the second grazing trial, finisher ostriches were allowed to graze lucerne pastures at two different stocking rates (10 and 15 birds/ha) while receiving either 0 or 800g supplementary feed/bird/day. Ostriches receiving supplementation had higher (P <0.05) mean end live weights than ostriches receiving no supplementation. Ostriches receiving supplementation reached a mean target slaughter weight of 95kg within the timespan of the trial, but ostriches receiving no supplementation did not. Stocking rate had no influence on mean end live weight of the birds. An interaction (P <0.05) was found between the level of supplementation and stocking rate for ADG of the birds. Stocking rate influenced ADG only for birds receiving no supplementation. As stocking rate increased, ADG of birds receiving no supplementation declined. Results of the pasture data indicated an increasing level of replacement of grazed lucerne DM by supplementary feed as the trial progressed and this was more pronounced at the higher stocking rate of 15 birds per hectare. A high stocking rate seems to have had a gradual depressing effect on lucerne DM production, while the less severe levels of defoliation at a lower stocking rate promoted lucerne DM production. A digestibility trial was conducted with mature ostriches (12 months old) to investigate the effect of supplementation on intake and digestibility of nutrients, as well as to investigate the substitution effect that ostriches may display when they receive supplementary feed in addition to grazing. The same dietary treatments as in the first grazing study were given to ostriches while they were kept in metabolism crates. These diets were also fed to 20-week old roosters to obtain energy values for these diets for roosters. These energy values would be used to predict ostrich energy values for the same diets by means of a regression equation. For the roosters, each diet treatment was mixed with 50% maize to prevent digestive disorders and ensure maximum feed intake. Ostriches started to substitute supplementary feed for pasture when supplementation was supplied at levels higher than 62% (i.e. 1000g supplementary feed/bird/day) of total feed intake. For each increase of 100g in supplementary feed intake, pasture was replaced at a rate of 4.9%. Higher (P <0.05) total feed intakes were reached by ostriches if they grazed lucerne pastures and received supplementation than if they grazed pasture alone. Pasture grazing alone had lower (P <0.05) dry matter digestibility (DMD) and apparent metabolizable energy (AME) values for both ostriches and roosters than if pastures were supplied with a supplement. A significant stepwise regression could not be computed for the prediction of ostrich AME values from rooster AME values. The economics of different feeding systems (extensive versus intensive) were evaluated with an economic analysis, which was based on the same materials and methods and results of the first grazing trial. A margin above feed cost (MAFC) analysis was performed to evaluate the economic viability of the different feeding systems. The present value (PV) of the MAFC for the pasture-based system with 1000g/bird/day supplementation was only 8.3% lower than that of the feedlot system over a period of six years, while the PV of the cost of the same pasture-based system was 78.4% lower than that of the feedlot system. Birds finished on lucerne pasture with 1000g supplementation led to a saving of 57% in feeding costs if compared to a feedlot system. A sensitivity analysis of the MAFC revealed that the pasture-based system was less sensitive to changes in feeding costs than the feedlot system. Therefore, the unique circumstances of each ostrich producer will play a role in the decision whether to raise ostriches in a feedlot or on pastures.
AFRIKAANSE OPSOMMING: Die produksie van slagvolstruise in ‘n ekstensiewe weidingsstelsel met verskillende vlakke van aanvullende voeding is gedurende hierdie studie ge-evalueer. Twee weidingsstudies is uitgevoer. In die eerste studie is een groep afrondingsvolstruise (ses maande oud) in ‘n voerkraal geplaas en ‘n volledige afrondingsdieet gevoer. Die ander vier groepe is op besproeide lusernweiding geplaas (teen ‘n weidigtheid van 15 voëls/ha) en het onderskeidelik 1500, 1000, 500 en 0g aanvullende voeding/voël/dag ontvang. Weidingproduksie en -inname is gemeet. Daar was geen verskil (P >0.05) tussen die eindgewigte van die voerkraal volstruise en dié van die weidende voëls wat onderskeidelik 1500 en 1000g aanvullende voeding ontvang het nie. Die gemiddelde daaglikse toename (GDT) van die groep weidende voëls wat 1000g aanvullende voeding ontvang het was laer (P <0.05) as die GDT van die groep weidende voëls wat 1500g aanvullende voeding ontvang het, maar al drie hierdie groepe het ‘n gemiddelde teiken slaggewig van 95kg bereik binne die 154 dae van die studie. Weiding, tesame met die korrekte aanvullende voeding (van ten minste 1000g/voël/dag) kan volvoer rantsoene in die afrondingsfase van slagvolstruise vervang en kan dus ‘n belangrike rol speel ten opsigte van die produksie van hierdie voëls. Vir lusern inname is ‘n kwadratiese passing (P <0.01) tussen weiding droë materiaal (DM) inname (g/voël/dag) en aanvullende voeding inname (g/voël/dag) gevind. Die maksimum lusern inname (1692.8g/voël/dag) is bereik wanneer voëls 619.6g aanvullende voeding/voël/dag ingeneem het. In die tweede weidingsstudie, is afrondingsvolstruise (6 maande oud) toegelaat om lusern te bewei teen twee verskillende weidigthede (10 en 15 voëls/ha) en het ook 0 of 800g aanvullende voeding/voël/dag ontvang. Volstruise wat aanvullende voeding ontvang het, het hoër (P <0.05) gemiddelde eindgewigte bereik as volstruise wat geen aanvullende voeding ontvang het nie. Volstruise wat aanvullende voeding ontvang het, het ook die teiken slaggewig van 95kg bereik binne die tydsduur van die studie, terwyl die volstruise wat geen aanvullende voeding ontvang het nie, nie daarin kon slag nie. Weidigtheid het nie ‘n invloed (P >0.05) gehad op die eindgewigte van die voëls nie, maar ‘n interaksie (P <0.05) is gevind tussen vlak van aanvullende voeding en weidigtheid wat GDT van die voëls betref. Weidigtheid het GDT beïnvloed slegs vir volstruise wat geen aanvullende voeding ontvang het nie. Soos die weidigtheid van die voëls wat geen aanvullende voeding ontvang het nie, toegeneem het, het die GDT van hierdie voëls afgeneem. Ontleding van die weidingsdata het ‘n toenemende vlak van verplasing van die weiding met aanvullende voeding getoon soos die studie gevorder het en dit was meer merkbaar by die hoër weidigtheid. Die hoër weidighteid het ook gelei tot ‘n geleidelike afname in lusern DM produksie, terwyl die minder aggressiewe vlakke van ontblaring by die laer weidigtheid lusern DM produksie bevorder het. ‘n Verteringsstudie is gedoen met volwasse volstruise (12 maande oud) om die invloed van aanvullende voeding op inname en verteerbaarheid van nutriente te toets, asook om die substitusie effek wat volstruise mag toon wanneer hulle aanvullende voeding ontvang op weiding, te ondersoek. Dieselfde dieet behandelings as in die eerste weidingsstudie is vir die volstruise gegee terwyl hulle in metabolisme kratte aangehou is. Hierdie diëte is ook aan 20-week oue hane gevoer om die energie waardes van die diete vir hane te verkry. Hierdie energiewaardes sal dan gebruik word om volstruis energiewaardes te voorspel vir dieselfde diëte met behulp van ‘n regressie vergelyking. Vir die hane is elke dieet gemeng met 50% mielies om inname te handhaaf en spysverteringsstoornisse te voorkom. Volstruise het weiding begin verplaas met aanvullende voeding sodra die vlak van aanvullende voeding hoër as 62% (d.i. meer as 1000g aanvullende voeding/voël/dag) van die totale inname van die voëls was. Vir elke 100g toename in aanvullende voeding, word weiding verplaas teen ‘n tempo van 4.9%. Weiding, tesame met aanvullende voeding, het gelei tot hoër totale droë material (DM) voerinnames by volstruise as wanneer weiding alleen beskikbaar was. Wanneer weiding alleen voorsien was, was daar laer (P <0.05) verteerbaarhede van DM en waarskynlike metaboliseerbare energie (WME) waardes vir beide volstruise en hane as wanneer die weiding voorsien word met aanvullende voeding. Geen betekenisvolle stapsgewyse regressie kon gevind word om volstruis energie waardes uit hoender energie waardes te voorspel nie. Die ekonomie van verskillende sisteme (ekstensief versus intensief) is in hierdie studie vergelyk en is gebaseer op dieselfde materiaal en metodes en resultate van die eerste weidingsstudie. ‘n Marge bo voerkoste analise is gebruik om die ekonomiese lewensvatbaarheid van die sisteme met mekaar te vergelyk. Die huidige waarde van die marge bo voerkoste van die weidingssisteem waar 1000g aanvullende voeding gevoer word was 8.3% laer as dié van die voerkraal sisteem oor ‘n periode van ses jaar. Daarteenoor was die huidige waarde van die koste van dieselfde weidingssisteem 78.4% laer as dié van die voerkraal sisteem. Die weidingssisteem waar volstruise 1000g aanvullende voeding ontvang het, het ‘n besparing van 57% in voerkoste getoon wanneer dit met die voerkraal volstruise vergelyk is. ‘n Sensitiwiteitsanalise van die marge bo voerkoste het getoon dat die weidingssisteem minder sensitief is vir wisselende voerkoste as die voerkraal sisteem. Die unieke omstandighede van elke produsent sal ‘n rol speel in sy keuse om volstruise op weiding of in ‘n voerkraal af te rond.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 1985.
The domestication of ostriches and commercial ostrich breeding has a long and interesting history. Orstriches were successfully domesticated in Algeria during 1857 and also successfully bred in Italy during 1859. In South Africa the domestication of wild ostriches started in the Cape Colony with 80 tame birds during 1865. This number increased to 32 247 birds within ten years (De Mosenthal, 1877). Ostrich farming reached a peak during 1913 with 757 000 birds (De Jager, 1985, personal communication). Currently (1985) there are approximately 120 000 domesticated ostriches in South Africa. The commercial production of ostrich meat started in 1958 and the first abattoir was built in 1964. At the present moment 85 000 birds are slaughtered anually. Although the income from the carcass of a 14 month old ostrich comprise only 15% of the total income of a 14 month old bird (With the hide comprising 65% and, the first harvest feathers 20%), the subjects of carcass characteristics and meat quality has long been neglected. Very little is known about the anatomy of the skeleton and muscles of the ostrich, the post mortem reactions of these muscles and the effects of different slaughtering, chilling and deboning practices. The necessity of the above mentioned have proved very usefull in the beef, sheep, pork and poultry industries. With this present study we described the essential skeletal and muscular anatomy and included well known practices to the meat industry, such as electrical stimulation of the carcasses, post mortem pH monotoring of certain muscles, different deboning practices and vacuum packed ageing of selected cuts of ostrich meat. The obtained results are in agreement with general meat science, with expected inter-species variation, e.g. where the final pH-values of pork is relatively low at approximately 5,5; that of beef is higher at 5,7 and ostrich meat even higher at 6,0. Certain other fields of essential research are pointed out in this study, such as the growth and development of the ostrich, as well as certain basic biochemical research on the meat of the ostrich.

Thesis (MSc (Biochemistry))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The ostrich industry in South Africa is currently threatened by respiratory disease in feedlot ostriches which causes a dramatic loss in production. Ms01, Ms02 and Ms03 were identified as the three ostrichspecific mycoplasmas to be associated with this respiratory disease in ostriches of South Africa. The ostrich-specific mycoplasmas have a major impact on ostrich production and for this reason there is a serious need for treatment for these infections. For this reason, the ostrich industry has undertaken an investigation into the development of vaccines against mycoplasma infections. In this study, an approach to DNA vaccine development will be investigated and applied, specifically for the ostrich mycoplasma Ms02. Firstly, the whole genome of Ms02 was sequenced using GS FLX sequencing technology. The contiguous sequences obtained from the whole-genome sequencing were analysed bioinformatically which included the annotation of the contiguous sequences and the subsequent search for a vaccine candidate gene for the development of a DNA vaccine. The P100 gene of Ms02, which showed a high degree of homology with the P100 gene of the human pathogen M. hominis, was chosen as a vaccine candidate gene for the development of a DNA vaccine. The P100 gene was successfully cloned and subsequently modified by means of site-directed mutagenesis to correct for alternative codon usage, where after the modified P100 gene was subcloned into the mammalian expression vector, pCI-neo for vaccination trials in the near future.
AFRIKAANSE OPSOMMING: Die volstruisbedryf van Suid-Afrika is tans bedreig deur 'n respiratoriese siekte in voerkraal volstruise wat lei tot aansienlike verliese in volstruisproduksie. Ms01, Ms02 en Ms03 is geïdentifiseer as die drie volstruis-spesifieke mikoplasmas wat 'n rol speel in hierdie respiratoriese siektes van volstruise in Suid- Afrika. Die drie volstruis-spesifieke mikoplasmas het 'n groot impak op die produksie van volstruise en om hierdie rede is daar 'n ernstige behoefte aan 'n behandeling van hierdie infeksies. Ten einde mikoplasma infeksies in volstruise te voorkom, het die Suid-Afrikaanse volstruisbedryf 'n ondersoek geloods na moontlike strategieë vir entstof ontwikkeling. In hierdie studie, is 'n benadering van DNA entstof ontwikkeling ondersoek en toegepas, spesifiek teen die volstruis mikoplasma Ms02. Eerstens, is die volledige Ms02 genoomvolgorde bepaal deur gebruik te maak van GS FLX volgordebepalingstegnologie. Die gedeeltelike volgordes verkry vanaf die heelgenoom volgordebepaling is bioinformaties geanaliseer wat die annotering van die gedeeltelike volgordes asook die soektog vir 'n kandidaat entstof geen vir die ontwikkeling van 'n DNA entstof ingesluit het. Die P100 geen van Ms02, wat hoë homologie met die P100 geen van die menslike patogeen M. hominis getoon het, is gekies as die kandidaat entstof geen. Die P100 geen is suksesvol gekloneer en gemodifiseer deur middel van setelgerigte mutagenese om die P100 geen geskik te maak vir die invoeging in die soogdier ekspressie vektor, pCI-neo vir toekomstige entstofproewe.

O objetivo deste trabalho foi estudar os níveis séricos dos hormônios esteróides (estradiol e progesterona) e analisar as possíveis relações destes com o desenvolvimento do comportamento reprodutivo em fêmeas jovens de avestruzes (Struthio camelus) durante a maturação sexual. No primeiro experimento, duas fêmeas jovens foram avaliadas, três vezes por semana, através de colheitas de sangue para dosagem de estradiol e progesterona e de observações para avaliação do comportamento reprodutivo. No segundo experimento, 20 fêmeas jovens foram selecionadas de acordo com a intensidade de comportamento reprodutivo e tiveram seu comportamento reprodutivo monitorado semanalmente. Foram realizadas colheitas de sangue semanais nos mesmos dias das observações comportamentais. No primeiro experimento, através da comparação das médias dos valores de estradiol nas fases de presença (CCOMP) ou ausência de comportamento reprodutivo (SCOMP), verificou-se uma igualdade entre as médias nas duas fêmeas estudadas e não foi verificada correlação entre os níveis séricos de estradiol e o comportamento reprodutivo. No segundo experimento, a comparação das médias de estradiol entre as amostras dos animais SCOMP e CCOMP apresentou diferença significativa. A comparação das médias entre as 4 categorias comportamentais estabelecidas - sem comportamento (SCOMP), com baixo comportamento (COMPBX), com alto comportamento sem aceitação de cópula (COMPALTSACC), com alto comportamento com aceitação de cópula (COMPALTCACC) - demonstraram haver diferença significativa entre os valores de estradiol encontrados, também sendo verificada correlação entre as 4 categorias e os níveis médios de estradiol (r = 0,64). Para a progesterona, no primeiro experimento, os valores médios foram significativamente maiores nas amostras SCOMP do que nas CCOMP, sendo que a progesterona apresentou uma correlação negativa com a intensidade do comportamento reprodutivo nas duas fêmeas (r = -0,54 e r = -0,33). No segundo experimento, os valores médios de progesterona foram significativamente maiores nas amostras CCOMP do que nas amostras SCOMP. As médias de progesterona das 4 categorias comportamentais apresentaram diferenças significativas e houve correlação positiva (r = 0,43) dos níveis de progesterona com as 4 categorias comportamentais. Os resultados sugerem que exista uma relação entre os níveis de estradiol e progesterona e a modulação da intensidade de comportamentos reprodutivos, mas não necessariamente entre estes níveis hormonais e a iniciação destes comportamentos e que os perfis séricos de estradiol e progesterona em fêmeas de avestruz na fase de maturação sexual apresentam semelhanças com outras espécies de aves.
The purpose of this work was to study the serum levels of estradiol and progesterone and analyze their relationship with the development of the reproductive behavior in young female ostriches (Struthio camelus) during sexual maturity. The first experiment studied two young females, through blood samples, three times a week, for measurement of estradiol and progesterone and was performed behavioral observations at the same time. In the second experiment, twenty young female ostriches had their reproductive behavior monitored weekly and blood samples were collected for hormone assays in the same days of the observations. The results of the first experiment showed no differences between the mean of estradiol levels in the two phases, with and without reproductive behavior. In the same way there were no correlations between estradiol levels and frequency of behaviors. In the second experiment, there were significant differences between the mean of estradiol levels with and without reproductive behavior. When it was considered four categories of behavior (without behavior, low behavior, high behavior and no copulation posture, and high behavior and copulation posture display), the mean estradiol levels showed significant differences. There was positive correlation between the categories and the estradiol levels (r = 0,64). Regarding progesterone, the first experiment, demonstrated significantly higher hormonal levels in the absence than in the presence of reproductive behavior and a negative correlation between the occurrence of behaviors and the hormonal levels for both females (r = -0,54 and r = -0,33). In the second experiment, the means of progesterone levels were significantly higher in the phase with behavioral displays than with none. For the four behavioral categories, the means of progesterone levels differed significantly and showed a positive correlation (r = 0,43) with the reproductive behavior. The results suggest that there is a relationship between estradiol and progesterone levels and the occurence of the reproductive behavior, but not necessarily between these hormone levels and the initiation of the process. The hormonal levels of estradiol and progesterone found in ostriches were similar to some domestic avian species.

Includes abstract.
Thesis (M.Com. (Economics))--University of Cape Town, 2013.
Includes bibliographical references.
This thesis investigates the effect of exchange controls on trade of the Southern African Development Community (SADC). Restrictions on foreign exchange should be adjusted (liberalised to an extent) in order to harmonise policies between members, as an important part of the regional integration plan, which aims at the creation of a Monetary Union by 2018. The first step taken to examine the collateral effect of this on trade involves the construction of a new index, measuring exchange control restrictiveness (ECRI) across SADC countries over the last 10 years, based on the IMF’s Annual Report on Exchange Arrangements (AREAR).