Dissertations / Theses on the topic 'Protein sources in animal feed'

In Venezuela, four sheep fitted with rumen cannulas were fed the toxin-containing legumes Leucaena leucocephala (sun dried leaves and stems) and Canavalia ensiformis (grains). L. leucocephala did not have any apparent toxic effects on the animals, in spite of the presence of the toxic compounds 3,4 DHP and 2,3 DHP in the rumen. There were no significant effects on the rumen pH, concentrations of VFAs, microbial counts, rate of rice straw degradation or in the rumen outflow of liquids and solids. However, there was an increase in the concentration of ammonia in the rumen, and in the number of Gram negative rods isolated from the rumen of sheep when L. leucocephala was added to the diet. When C. ensiformis was supplemented the presence of canavanine in the rumen was confirmed. Sheep did not show signs of toxicity. There was no effect on rumen pH, microbial counts, degradation of rice straw or rates of outflow of liquids and solids from the rumen. There was a decrease in the rumen concentrations of valerate and ammonia and an increase in the numbers of Gram negative bacteria isolated from the rumen of sheep as the dietary inclusion of Canavalia increased. Several pure cultures capable of mimosine, 2,4 DHP and (in fewer cases) 3,4 DHP wre isolated. One of them, a Gram variable spore-forming rod, presumably a new species of Clostridium, was characterised. The presence of degraders of mimosine and DHP in the rumen presumably accounted for the lack of toxicity of L. leucocephala in Venezuela. The effect of canavanine on the growth and products of fermentation of pure cultures was independent of the Gram staining reaction and the results of experiments using media containing either peptides and amino acids or free amino acids alone suggest that canavanine may have an effect on peptide hydrolysis.

The studies reported in this thesis were carried out to evaluate the effects of enzyme treatment on the nutritive value of three lupin species (L. luteus, L. albus and L. angustifolius) and evaluate their suitability as a source of protein for growing broilers. Some preliminary in vitro work on the effect of quinolizidine alkaloids on bacteria from poultry excreta was carried out. Furthermore the use of near infrared spectroscopy (NIRS) as an alternative technique for assessing the chemical composition and nutritive value (such as metabolizable energy and digestibilities) was investigated. Compositional analyses of the various lupins, fractions and diets were conducted. The chemical composition of the lupin seeds used in this study showed a high crude protein content and a variable content in ether extract and neutral detergent fibre. The alkaloid content of the seeds was determined and allowed the classification of the lupin into bitter (L. luteus cv Cardiga), semi-sweet (L. albus cv Estoril) and sweet (L. albus from France and L. angustifolius from Australia) seeds. Alkaloids from lupins decrease feed consumption and may affect the digestive capacity of the animal. A preliminary study on the effects of sparteine and alkaloids extracted from L. luteus seeds on bacteria from poultry excreta indicated that extracts of alkaloids from L. luteus had an inhibitory effect on coliform growth that was not, however, as great as that of sparteine. Sparteine, essentially prevented growth of coliforms at concentrations of 10 g dm-3. Lactobacilli were apparently not directly affected by the lupin extract of alkaloid or the isolated sparteine. This in vitro work suggests that it may be possible to influence the gut microflora in a beneficial manner by using the appropriate concentration of the appropriate alkaloids. A set of tube feeding experiments (by gavage) were carried out to evaluate the effect of different enzymes on the nutritive value of L. luteus (cv. Cardiga) and L. albus (cv. Estoril) seeds. The first experiment was a preliminary one which allowed the modification of the tube feeding assay in order to suit the characteristics of the test materials used in this study. The following six experiments tested the effects of pre-incubation, as a wet mash, of a polygalacturonase, five proteases, a pectinase and an [Special character omitted]-galactosidase at variable levels, on the nutritive value of L. luteus (cv Cardiga) and L. albus (cv. Estoril). The nutritive value of the lupin seeds was evaluated essentially by measuring metabolizable energy (ME) and amino acid (AA) digestibilities. Results indicated that L. albus seeds, irrespective of enzyme treatment, had a higher ME expressed as TMEn than L. luteus seeds. Carbohydrase containing enzyme preparations, caused variable improvements in the ME value of lupin seeds. Polygalacturonase caused a significant increase in the ME of L. luteus seeds, which may have been mediated by an increase in protein digestibility as shown by improvements in the AA digestibility. Increased concentrations of pectinase tended to be more effective in the improvement of ME of L. albus, while increasing concentrations of a-galactosidase were so for L. luteus. The fact that the carbohydrases acted differently upon the two lupin species was probably due to their different concentration in constituent carbohydrates. Pre-incubation with exogenous proteases decreased the ME of the lupin seeds. The reasons for the depression were not clear, however high concentrations of proteases, expressed as U kg-1 of lupin seeds, may have interfered with the gastro intestinal tract and also with the endogenous enzymes of the bird resulting in reduced utilisation of the pre-incubated material. A growth experiment was design to investigate the effects of the inclusion of L. luteus (cv. Cardiga), L. albus (from France) or L. angustifolius (from Australia) as the main or secondary source of protein in diets for growing broilers. Lupin seeds were either pre-incubated as a wet mash, or the lupin containing diets were supplemented with a carbohydrase, a protease or a mixture of both. Diets were fed to the animals over a three week period. The results obtained tended to support the hypothesis that the enzymes had little effect on the other dietary ingredients but had their main effects on the lupins in the diets.

A study was conducted to evaluate the use of Leucaena leucocephala leaf meal (LLM) as a protein supplement for pigs. In addition, an evaluation of detoxifying LLM, by sun-drying, water-soaking, or treating with ferrous sulphate (FeS04) solution was undertaken. The research involved two experiments; a growth study and a metabolic study. In the growth study sixteen, 12 weeks old Large White x Landrace pigs (average body weight 22.9 ± 2.12 kg) were fed four experimental rations; a commercial grain-based grower /finisher ration (control); or a ration containing 20% of either sun-dried LLM, water-soaked LLM, or FeS04-treated LLM, replacing the basal diet. There was a significant (P<0.05) decrease in liveweight gain, feed intake and feed conversion efficiency in pigs fed the ration containing sun-dried LLM. Growth rate, feed intake and feed conversion efficiency were not affected by the addition of water-soaked and FeS04-treated LLM to the basal diet. Triiodothyronine (T3) and thyroxine (T4) levels in the blood plasma were not affected by the dietary treatments. However, addition of FeS04-treated LLM to the basal diet significantly (P<0.05) decreased the back fat thickness of the pigs. In the metabolic study, the digestible dry matter (DDM) and digestible CP (DCP) were measured as well as mimosine, 3-hydroxy-4-(1H) pyridone (3,4-DHP) and 2,3DHP output in the faeces and urine.
Addition of water-soaked LLM to the diet significantly (P<0.05) lowered the DDM of the diet, whereas addition of FeS04-treated LLM significantly (P<0.05) reduced the DCP. Sun-drying, water-soaking and treatment of LLM with FeS04 solution, did not enhance the output of mimosine or 3,4-DHP in the urine and faeces. The results suggest that water soaking or treatment with FeS04 solution reduces the antinutritional factors (presumably including mimosine) and therefore improves the nutritional quality of LLM containing diets for pigs.

Thesis (MScAgric)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: The objective of this study was to determine the effect of extrusion, as a method of heat treatment, on the dry matter (DM) and crude protein (CP) degradability parameters of various vegetable protein sources commonly used in the Western Cape Province, South Africa. The feedstuffs used were lupins (LUP), full fat soybeans (SB), full fat canola seeds (FCS), soybean meal (SBM), canola meal (CM) and sunflower meal (SFM). In the first trial, the degradability parameters were determined according to an in sacco degradability procedure. Four non-lactating Holstein cows, fitted with rumen cannulae, were used in the trial and all cows received the same basal lactation diet. The samples were incubated in dacron bags and bags were removed at intervals of 0, 2, 4, 8, 16, 24 and 48 hours. Dry matter and CP disappearance values were determined and fitted to a onecompartment model by means of an iterative least-square procedure in order to determine the DM and CP degradability parameters. Results indicated that extrusion significantly lowered the effective degradability of the DM-fraction (20.1% on average) of all the feedstuffs, except LUP, and the effective degradability of CP in all the raw materials (27% on average). The second trial was an in vitro degradability trial that ran parallel with the in sacco degradability trial and was done with the aid of a DaisyII Incubator (ANKOM Technology Corp., Fairport, NY). The same feedstuffs were tested in both trials. A composited sample of rumen liquor from two of the cows used in the in sacco trial was used for in vitro incubation of the samples. The data obtained in this trial were analyzed in a similar way to that of the in sacco trial. Due to a limited amount of residue left after incubation, CP disappearance could not be calculated at each time interval for SB and SBM in the in vitro trial. In this case, actual disappearance values after 8h were used to compare treatments. Extrusion significantly lowered the effective degradability (as determined in vitro) of DM in all the feedstuffs tested (16.8% on average), as well as the effective degradability of CP in LUP, FCS, CM and SFM (21.8% on average). A comparison of the actual disappearance values after 8 hours incubation indicated that extrusion also lowered the rate of CP disappearance for SB and SBM. The values obtained in the in vitro trial and those from the in sacco trial, for the same feedstuffs, were compared. It appeared as if the in vitro determined values were overestimations of the in sacco determined values. A regression analysis showed a high correlation between the actual in vitro CP disappearance values after 8h incubation and in sacco determined effective degradability values. The third part of this study was a set of chemical analysis to determine the effect of extrusion on certain nitrogen fractions of the feedstuffs tested in the above mentioned trials. Solubility in a mineral buffer solution was determined to estimate the potential rumen degradability of the protein. The buffer insoluble nitrogen (BIN) fraction of all the feedstuffs, except FCS, was significantly increased by extrusion. Extrusion lowered the acid detergent insoluble nitrogen (ADIN) content of all feedstuffs, except FCS, which could imply that the temperature reached during extrusion (115°C - 120°C) was not high enough to cause damage to the protein. The neutral detergent insoluble nitrogen (NDIN) fraction of extruded SB, SBM, CM and SFM was significantly higher than that of the raw feedstuffs. Extrusion left the NDIN-fraction of FCS and LUP unaltered. Comparison of the NDIN : ADIN ratio of extruded with that of the raw feedstuffs provided reason to believe that extrusion had a positive effect on all feedstuffs (except FCS). Extrusion appears to be a useful method to decrease rumen degradation of vegetable protein sources, without causing heat damage. Furthermore, this means that protein sources of which the use have been limited due to its high rumen degradable protein (RDP) content, could be included in diets at higher levels following extrusion. The protein sources mentioned are also good sources of energy and the combination of energy and rumen undegradable protein (RUP) in the diet of the high-producing dairy cow could only be beneficial.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van ekstrusie op die droëmateriaal (DM) en ruproteïen (RP)-degradeerbaarheidsparameters van verskeie plantaardige proteïenbronne wat algemeen in die Wes-Kaap (RSA), gebruik word, te bepaal. Ekstrusie is ‘n metode van hitteprosessering wat algemeen gebruik word deur plaaslike en internasionale veevoervervaardigers. Die volgende grondstowwe is geëvalueer: lupiene, volvet sojabone, volvet canolasaad, sojaboon-oliekoekmeel, canola-oliekoekmeel en sonneblom-oliekoekmeel. In die eerste proef is die degradeerbaarheidsparameters met behulp van ‘n in sacco studie bepaal. Vier droë Holstein koeie met rumen kannulas is in die studie gebruik en al vier koeie het dieselfde basale dieet ontvang. Monsters is in dacronsakkies geïnkubeer en die sakkies is uit die rumen verwyder na onderskeidelik 0, 2, 4, 8, 16, 24 en 48 uur intervalle. Die waardes van DM- en RP- verdwyning is bereken en dan met ‘n iteratiewe kleinste kwadraat prosedure op ‘n een-kompartement model gepas om die in sacco DM- en RPdegradeerbaarheidsparameters te bepaal. Die resultate van die studie het getoon dat ekstrusie die effektiewe degradeerbaarheid van die DM-fraksie van al die grondstowwe, behalwe lupiene, betekenisvol verlaag het (met gemiddeld 20.1%), asook die effektiewe degradeerbaarheid van die RP-fraksie van al die grondstowwe (met gemiddeld 27%). Die tweede proef was ‘n in vitro-degradeerbaarheidsstudie wat met behulp van ‘n ANKOM DaisyII Inkubeerder uitgevoer is en wat parallel met die in sacco-studie gedoen is. Dieselfde grondstowwe is in beide proewe geëvalueer. ‘n Saamgestelde monster van die rumenvloeistof van twee van die koeie wat vir die in sacco-studie gebruik is, is gebruik vir die in vitro-inkubasie van die monsters. Data-verwerking is op ‘n soortgelyke wyse as dié van die in sacco-studie uitgevoer. As gevolg van ‘n beperkte hoeveelheid residu na afloop van die inkubasies, kon die RP-verdwyning vir volvet sojabone en sojaboon oliekoekmeel nie bereken word nie. In hierdie geval is waargenome verdwyningswaardes na 8h gebruik om behandelings te vergelyk. Hierdie studie het getoon dat ekstrusie die effektiewe degradeerbaarheid van DM (soos in vitro bepaal) in al die getoetste grondstowwe betekenisvol verlaag het (met gemiddeld 16.8%). Die effektiewe degradeerbaarheid van RP in lupiene, volvet canola saad, canola oliekoekmeel en sonneblom oliekoekmeel is ook betekenisvol verlaag (met gemiddeld 21.8%). ‘n Vergelyking van die oorspronklike verdwyningswaardes van volvet sojabone en sojaboon oliekoekmeel na ‘n inkubasieperiode van 8 ure het ook getoon dat ekstrusie die tempo van RP-verdwyning uit die rumen vertraag het. Die in sacco- en in vitro-bepaalde waardes vir elke grondstof is vergelyk en dit kom voor asof die in vitro-waardes oorskattings van die in sacco-waardes is. ‘n Regressie-analise het verder getoon dat daar ‘n hoë korrelasie was tussen die waargenome in vitro RPverdwyningswaardes na 8 ure inkubasie en die beraamde effektiewe degradeerbaarheid, soos in sacco bepaal. Die derde deel van die studie was ‘n stel chemiese analises wat uitgevoer is om die effek van ekstrusie op sekere stikstof (N)-fraksies van die grondstowwe, wat in bogenoemde proewe gebruik is, te bepaal. Die oplosbaarheid van N in ‘n mineraal-bufferoplossing kan gebruik word as aanduiding van die potensiële rumendegradeerbaarheid van die proteïen. Die bufferonoplosbare N-fraksie van al die grondstowwe (behalwe volvet canolasaad) is betekenisvol verlaag deur ekstrusie. Ekstrusie het ook die suur-onoplosbare N-fraksie (ADIN) van al die grondstowwe (behalwe volvet canolasaad) betekenisvol verlaag. Dit kan moontlik daarop dui dat die temperatuur wat tydens ekstrusie (115°C - 120°C) bereik is, nie hoog genoeg was om die proteïen in die grondstowwe te beskadig nie. Ekstrusie het die N-fraksie wat onoplosbaar was in ‘n neutrale oplossing (NDIN) betekenisvol verhoog in volvet sojabone, sojaboonoliekoekmeel, canola-oliekoekmeel en sonneblom-oliekoekmeel en dit onveranderd gelaat in lupiene en volvet canolasaad). Die verhouding van NDIN : ADIN van die geëkstrueerde grondstowwe is vergelyk met dié van die rou grondstowwe. Dit blyk dat ekstrusie wel ‘n positiewe effek op al die grondstowwe (behalwe volvet canolasaad) gehad het. Dit wil dus voorkom asof ekstrusie wel aangewend kan word om die rumendegradeerbaarheid van plantaardige proteïenbronne te verlaag sonder om die protein te beskadig. Dit kan daartoe lei dat proteïenbronne waarvan die gebruik voorheen beperk was as gevolg van die hoë rumen-degradeerbare proteïen-inhoud daarvan nou wel in rantsoene ingesluit kan word na die ekstrusie daarvan. Die proteïenbronne, soos genoem, is ook redelike bronne van energie en die kombinasie van energie en rumen nie-degradeerbare proteïen in die rantsoen van die hoog-produserende melkkoei kan slegs voordelig wees.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The objective of this study was to evaluate Dohne Merino sheep and Boer goats in terms of the degradable parameters of a high-fibre diet, a low-fibre diet and two vegetable protein sources commonly used in South Africa. Differences between species were evaluated following the potential differences within species. The feedstuffs used were those for the following diets: low-fibre diet (LF); high-fibre diet (HF); sunflower meal (SFM) oilcake; and soybean meal (SBM) oilcake. In the first trial, the digestible characteristics of the HF and LF diets were determined by means of a digestibility study. A 6 × 6 Latin square design was used to determine whether Dohne Merino sheep or Boer goat wethers differ regarding the digestibility characteristics of low- and high-fibre diets. The diets were fed once daily at 1.24 kg to all the wethers, which had ad libitum access to fresh water. Each period consisted of 10 days of adaptation and seven days of faecal and urinary sampling. The results indicated that the intake and digestibility characteristics of nutrients did not differ between sheep and goats. However, the different diets differed in terms of the nutrient intake and digestibility range of sheep and goats. The second trial was an in sacco degradability trial to determine the dry matter (DM) and crude protein (CP) degradability of the LF, HF, SBM and SFM diets. Six Dohne Merino and six Boer goat wethers were fitted with rumen cannulae so that they could be used in the trial. All wethers received the same basal diet. The samples were incubated in the rumen in polyester Dacron bags, with the bags being removed at intervals of 0h, 3h, 9h, 12h, 24h, 48h, 72h, and 96h for the LF and HF diets. All the oilcake was removed at intervals of 0h, 2h, 4h, 8h, 12h, 16h, 24h, 36h and 48h. The sheep and goats were found not to differ from one another in terms of effective degradability of any of the feedstuffs concerned. However, within species differences were observed. To establish a fully integrated outcome of degradability, the study described in the current thesis was structured in such a way that the in vitro trial ran parallel with the in sacco trial, being performed with the aid of a Daisy Incubator (ANKOM Technology Corp., Fairport, NY). Such a procedure was only adopted in relation to the SFM and SBM diets in order to evaluate their in vitro data in relation to the in sacco data. The same oilcake was tested in the case of both trials, with the composite sample of rumen liquid of four sheep or goats, which was used in the in sacco trial, also being used in the in vitro study. In the study, DM disappearance values were determined and fitted to a single-compartment model by means of an iterative least-square procedure in order to determine the DM and CP degradability parameters. The DM used in vitro or in sacco was compared, using the actual values obtained after 8h incubation, due to only a limited amount of residue being left after incubation. In the study, the in vitro method overestimated the digestibility of SBM by 37% to 39% and the digestibility of SFM by 17% to 20% compared with that found to occur in the in sacco method. In vitro DM disappearance values for all SBM samples were found to be higher than those that were detected in the SFM samples. The percentage of in vitro true digestibility parameters was also calculated. No significant differences were found between species for effective degradability, though differences were observed within species between the two substrates concerned. In conclusion, the sheep and goats used in the study were not found to differ in terms of digestion parameters when they were compared on different types of roughage or protein sources. However, within species differences were, indeed, found to occur. Sheep and goats digested the SBM better than they did the SFM.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om te bepaal of Dohne Merino skape verskil van Boerbokke in terme van degradeerbaarheidsparameters van ‘n hoë vesel-, ‘n lae veseldieët en twee plantaardige proteïenbronne wat algemeen in Suid-Afrika gebruik word. Die verskille tussen spesies is ge-evalueer en daarna die potensiële verskille binne spesies. Die volgende grondstowwe is geëvalueer: ‘n laevesel-dieët (LF), ‘n hoëvesel-dieët (HF), sonneblom-oliekoekmeel (SFM) en sojaboon-oliekoekmeel (SBM). In die eerste proef is die degradeerbaarheidsparameters van die HF dieët en die LF dieët met behulp van ‘n verteerbaarheidstudie bepaal. Dohne Merino hamels of Boerbok kapaters was gebruik om te bepaal of skape en bokke verskil in terme van inname en degradeerbaarheid van voedingstowwe wanneer hul hoë- en lae vesel voere gevoer word. Al die hamels en kapaters het ad libitum toegang tot vars water gehad en hul was een keer per dag (1.24 kg) gevoer. Elke periode het bestaan uit ‘n 10 dag aanpassingsperiode en ‘n toegelate 7 dae vir mis- en urienmonster versameling. Die resultate het aangedui dat die inname- en degradeerbaarheidsparameters van nutriënte beinvloed word deur verskillende diëte binne spesies. Geen verskille is gevind tussen spesies wanneer daar hoë- en lae kwaliteit voere gevoer is nie. Die tweede proef was ‘n in sacco-degradeerbaarheidsstudie om te bepaal wat die droë materiaal (DM) en ruproteïen (RP) verteerbaarheidsparameters van die HF dieët, die LF dieët, die SBM en die SFM is. Ses Dohne Merino’s en ses Boer bokke met rumen kanullas is in die studie gebruik en al die diere het dieselfde basale dieët ontvang. Die monsters is in die rumen geïnkubeer in poliester dakronsakkies en die sakkies is verwyder na onderskeidelik 0 uur, 3 uur, 9 uur, 12 uur, 24 uur, 48 uur, 72 uur en 96 uur intervalle. Laasgenoemde intervalle was geldig vir die lae vesel- en hoëveseldieët. Die oliekoeke se intervalle het verskil en is verwyder na 0 uur, 2 uur, 4 uur, 8 uur, 12 uur, 16 uur, 24 uur, 36 uur en 48 uur. Daar was geen verskille tussen spesies in effektiewe degradeerbaarheid nie, alhoewel verskille voorgekom het binne spesies. Skape verteer veselagtige grondstowwe meer effektief terwyl bokke weer hoë proteïn bevattende grondstowwe beter verteer. Om ‘n volkome geïntegreede uitkoms van degradeerbaarheid te bewerkstellig is die in vitro proef en die in sacco proef gelyktydig gedoen. Die in vitro-degradeerbareheidstudie is met behulp van ‘n ANKOM Daisy Inkubeerder uitgevoer (ANKOM Tegnologie Korp., Fairport, NY) vir net die oliekoek behandelings. Gedurende die studie is dieselfde oliekoeke gebruik. ‘n Saamgestelde monster van die rumenvloeistof van vier van die skape of bokke wat vir die in sacco-studie gebruik was, is gebruik vir die in vitro-inkubasie van die monsters. DM verdwyningparameters is bereken en dan met ‘n interaktiewe kleinste kwadraat prosedure op ‘n een-kompartement model gepas om die in sacco DMdegradeerbaarheidsparameters te bepaal. Die DM verdwyning, na 8h inkubasie, was gebruik om die in vitro en die in sacco metodes met mekaar te vergelyk, weens ‘n beperkte residu na die afloop van die elke inkubasiestudie. Tydens die studie het die in vitro metode degradering oorskat in vergelyking met die in sacco metode. DM verdwyningswaardes vir al die SBM monsters was hoër in vitro as die SFM monsters. In die studie is die persentasie in vitro ware degradeerbaarheidswaardes bereken. Geen verskille is opgemerk tussen spesies vir effektiewe degradeerbaarheid nie. Daar was wel verskille binne spesies. Om af te sluit het dit voorgekom dat skape en bokke nie verskil aan degradeerbaarheidswaardes wanneer daar ‘n vergelyking was tussen verskillende vesels- en proteϊenbronne nie, alhoewel verskille voorgekom het binne spesies. Skape en bokke het SBM effektief beter verteer as SFM.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: In recent years, the aim of the production of broilers became more focused on the increase of the performance of the birds in order to increase profit. To obtain an increased performance with broiler chicks, it is necessary to look at the development of their gastrointestinal tract, the feed requirements and the ability to digest certain nutrients in the period post hatch. Research have shown clear evidence of increased performance of chicks by the inclusion of certain carbohydrate and protein sources in the prestarter diets, but in contrast to this there are also some research that found no significant effects on the performance of broilers when certain carbohydrate and protein sources were included in the pre-starter diet. Therefore, the purpose of this study was to investigate the effect that a product containing specific carbohydrate and protein sources, included in the pre-starter diets of broiler chicks, would have on their performance. It was believed that the products to be tested would result in increased performance of the chicks in the following growth phases. Special emphasis was placed on the average daily gain (ADG), feed intake, cumulative feed intake, feed conversion ratio (FCR), European production efficiency factor (EPEF) and the protein efficiency ratio. Different inclusion levels of the different raw materials were investigated in the first trial. Three raw materials and a control were compared using a summit dilution process at 100:0, 66:34, 50:50, 34:66 and 0:100. Specific production parameters such as ADG total live weight gain, feed intake per week, cumulative feed intake, FCR, EPEF and PER were measured and calculated in order to determine if there were any significant differences between the treatments with the different raw material inclusions on the performance of the chicks. No significant differences (P>0.05) were found between the 13 treatments for the ADG, total live weight gain, feed intake per week, cumulative feed intake, FCR, EPEF and PER. The results therefore indicated that there were no significant differences between the different inclusion levels of the different raw materials and no significant differences for the production parameters for animals receiving diets with various levels of the three raw materials. It is thus concluded that these raw materials can be successfully utilised in pre-starter diets of broiler chicks. The effect of the contribution of sugar to the metabolisable energy (ME) of the raw materials was tested in a commercial grower trial. The three raw materials had inclusion levels leading to supply of either 12% or 18% of the ME in the form of sugar. No significant differences were found between the seven treatments for ADG, total live weight gain, feed intake per week, cumulative feed intake, FCR, EPEF or the PER. It was concluded that the percentage in contribution of sugars between 12 and 18% to the ME of the prestarter diets had no significant effects on the production parameters tested.
AFRIKAANSE OPSOMMING: Met die produksie van braaikuikens word daar deesdae al hoe meer klem gelê op die verhoging van die produksie van die kuikens om dan dus ‘n verhoging in die wins te bewerkstellig. Om hierdie verhoogde produksie by braaikuikens te kan bereik, is dit nodig om na eienskappe van die kuiken soos die ontwikkeling van die spysvertering stelsel, die nutrient- behoeftes van die kuiken en die vermoë om sekere nutriënte te kan verteer in die periode na uitbroei. Sommige navorsing het gewys dat die insluiting van sekere koolhidraat – en proteïen bronne in die voor-aanvangs diëete van braaikuikens, lei tot ‘n positiewe effek op die produksie van die kuikens, waar ander navorsing geen effek gevind het nie. Daarom was die doel van die huidige navorsing gewees om te toets wat die effek van die insluiting in die voor-aanvangs dieet van braaikuikens ‘n sekere produk met ‘n spesifieke koolhidraat –en proteïen bron samestelling op die produksie van die kuikens sal wees in die daaropvolgende fases. Dit was verwag dat die insluiting van hierdie produkte in die voor-aanvangs diëte van braaikuikens ‘n positiewe effek sou hê op die produksie van die kuikens. Spesiale klem was gelê op die parameters soos gemiddelde daaglikse toename (GDT) voer inname, kumulatiewe voer inname, voeromset verhoudings (VOV) Europese produksie doeltreffendheids- faktor (EPEF) en die proteïen doeltreffendheids faktor (PER). Verskillende insluitings vlakke van die verskillende produkte wat getoets is, is in die eerste proef ondersoek. Die drie produkte is deur middel van ‘n piek verdunnings proses by verhoudings van 100:0, 66:34, 50:50, 34:66 en 0:100 met mekaar vergelyk. Spesifieke produksie- parameters soos die GDT, lewende massa, weeklikse voer- inname, kumulatiewe voer- inname, VOV, EPEF en die PER is gemeet. Geen betekenisvolle verskille (P>0.05) was vir die 13 behandelings verkry nie. Die resultate het derhalwe getoon dat daar geen betekenisvolle verskille tussen die verskillende insluitings vlakke van die onderskeie produkte was nie en dat daar geen betekenisvolle tussen die produksieparameters van die kuikens wat die diëte met die verskillende insluitingspeile van die drie roumateriale ontvand het, was nie. Daarom is tot die slotsom gekom dat hierdie roumateriale suksesvol in die vooraanvangsdieet van braaikuikens aangewend kan word. Die effek van die bydrae van die suiker tot die metaboliseerbare energie (ME) van die produkte was in ‘n kommersiële groei proef getoets. Die drie rou materiale was by beide 12- en 18% ingesluit. Geen betekenisvolle verskille (P>0.05) was vir die sewe behandelings vir GDT, lewende massa, weeklikse voer- inname, kumulatiewe voer- inname, VOV, EPEF en PEF verkry nie.

Feed intake is a key factor affecting pig performance; thus, the objective of these studies was to assess a variety of factors that could potentially affect intake in pigs in different production stages. Studies were conducted to determine the effects of flavor and diet complexity, Appetein™ (an alternative protein source), and graded levels of salt on swine feed intake and feed preference. Two newly developed flavors were used in nursery pig diets. The use of the two flavors did not increase feed intake (P > 0.05). Nursery pigs actually showed a preference for the control diet. Complex diet formulation does increase feed intake (P < 0.03) in nursery pigs when diets are not over-formulated. When flavor was added to lactation diets sow feed intake did not change compared to the control. The flavor did not affect litter performance (P > 0.05). When Appetein™ was added to lactation diets at 0.5%, pig weight and litter weight were numerically greater for the sows fed Appetein™ but not significantly so. Appetein™ did not affect feed intake. When nursery pigs were fed graded levels of salt (0.1, 0.5, and 0.8%) feed intake increased (P < 0.01) as salt level increased. Nursery pigs also preferred (P < 0.05) 0.8% salt over other levels the first two weeks after weaning when given a choice among diets.

Dissertação de Mestrado Integrado em Medicina Veterinária
Microbubbles (MBs) are highly stable air-filled bubbles with mean diameters between 0.1 and 100 μm. As interest in their application in food science grows (e.g. to bring textural or functionality benefits to food products), it is becoming increasingly important to understand the mechanisms behind their formation. This thesis addresses the factors influencing the production of protein-coated microbubbles, using whey protein and egg-white protein mixtures as surfactants, by a process of emulsification followed by the cross-linking of protein molecules under high-intensity ultrasound. Five commercially available whey protein isolates were tested and only one generated microbubbles (Volac®), which led us to produce our own whey protein concentrate (SPC) from raw milk, by utrafiltration. Yield and size of the microbubbles were determined for both Volac and SPC mixtures, as a function of various experimental parameters – pH, protein concentration, incubation temperature and sonication time – and the best conditions were selected by calculating the amount of air incorporated. SPC produced more bubbles, which were also more stable, resisting for at least one month at ambient temperature. Protein composition of the mixtures was determined and compared by SDS-PAGE and HPLC. Commercial and self-made whey proteins showed some differences in the amount of the three most predominant proteins in whey (β-LG, α-LAC and BSA) as well as in glycomacropeptides, which could explain the differences in ability of the proteins to adsorb at the interface. Finally, scanning electron microscopy gave some insights about the way whey and egg-white proteins arranged at the interface, analyzed in terms of shell thickness and surface smoothness.
RESUMO - PRODUÇÃO DE MICROBOLHAS PARA A INDÚSTRIA ALIMENTAR UTILIZANDO PROTEÍNAS DE ORIGEM ANIMAL - Microbolhas (MBs) são bolhas de ar altamente estáveis com diâmetros médios entre 0,1 e 100 μm. À medida que o interesse da sua aplicação em ciência alimentar vai aumentando (e.g. para melhorar a textura ou a funcionalidade dos produtos), torna-se cada vez mais importante perceber os mecanismos responsáveis pela sua formação. Esta tese estuda os factores que influenciam a produção de microbolhas revestidas por proteínas, utilizando como surfactantes misturas de proteínas do soro de leite e da clara de ovo. Esta produção foi levada a cabo por um processo de emulsificação seguido de interligação das moléculas proteicas submetidas a ultrasonificação. Foram testadas um total de cinco misturas de proteínas de soro de leite adquiridas comercialmente e apenas uma (Volac®) gerou microbolhas, pelo que um concentrado de proteínas do soro (SPC) foi obtido através de leite de vaca cru, por um processo de ultrafiltração. Para ambas as misturas, o rendimento e o tamanho das microbolhas foram determinados, em função de variados parâmetros experimentais – pH, concentração de proteína, temperatura de incubação e tempo de sonificação – e as condições ideais foram determinadas calculando o volume de ar incorporado. A mistura SPC produziu um maior número de bolhas, que por sua vez se revelaram mais estáveis, resistindo pelo menos um mês à temperatura ambiente. A composição proteica das misturas foi determinada e comparada por SDS-PAGE e HPLC. As misturas de proteínas do soro adquiridas comercialmente e produzidas por ultrafiltração revelaram algumas diferenças na quantidade das três proteínas predominantes (β-lactoglobulina, α-lactoalbumina e albumina do soro bovino) assim como em glicomacropéptidos, o que poderia explicar diferenças na capacidade de adsorção das proteínas da mistura na interface com o ar. Finalmente, ensaios de microscopia electrónica de varrimento forneceram alguns esclarecimentos acerca da forma como as proteínas se dispõem nas microbolhas, quando analisados em termos de espessura e textura do revestimento proteico.
http://hdl.handle.net/10400.5/6076

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.
Includes bibliography.
ENGLISH ABSTRACT: The objective of this study was to evaluate the use of Musca domestica (common house fly) larvae meal, as protein source, for broiler production. This was done by investigating the nutritive value of house fly larvae meal together with its total tract digestibility, potential toxicity and carcass characteristics of the broilers supplemented with house fly larvae meal. The proximate analysis of house fly larvae meal show that it contained, on a dry matter basis, a gross energy value of 20.10 MJ/kg, 60.38% crude protein, 14.08% crude fat and 10.68% ash and that the house fly pupae contained a gross energy of 20.42 MJ/kg, 76.23% crude protein, 14.39% crude fat and 7.73% ash. House fly pupae meal had the closest match of amino acid profile when compared with the ideal amino acid profile required by broilers and it has arginine relative to the lysine content closer to the ideal amino acid profile than the house fly larvae meal. The essential fatty acid, linoleic acid, was found at levels of 26.25 and 36.27% of the total fats for the house fly larvae and pupae meal respectively. House fly larvae meal supplementation did not induce gizzard erosion or showed toxicity (regarding the gastro intestinal tract, immune system and organ stress) in broilers. Results revealed that house fly pupae meal had higher total tract digestibilities for most nutrients than of the house fly larvae meal. House fly larvae meal had a crude protein total tract digestibility of 69% and that of pupae meal was 79%. Both larvae and pupae meal had high amino acid total tract digestibilities of all the amino acids analysed. The house fly larvae and pupae meal had an apparent metabolizable energy (AME) value of 14.23MJ/kg and 15.15MJ/kg respectively. The larvae meal total tract crude fat and crude fibre digestibilities were 94% and 62% respectively. The pupae meal total tract crude fat and crude fibre digestibilities were 98% and 58% respectively. House fly larvae meal supplementation in a three phase feeding system significantly increased average broiler live weights at slaughter, total feed intake, cumulative feed intake as well as average daily gain (ADG) when compared to commercial maize: soya oil cake meal diet. In direct comparison of larvae inclusion levels with fishmeal in isonitrogenous and isoenergetic diet, no significant differences were observed between a 10% house fly larvae and a 10% fish meal diets regarding performance characteristic. The 25% house fly larvae meal diet yielded significantly better average broiler live weights at slaughter, total feed intake, cumulative feed intake (from the second week until slaughter) as well as average daily gain when compared to the 25% fish meal diet in the growth phases. Carcass characteristics of the 10% larvae, 10% fishmeal and commercial diets were compared. Chicks that received either the 10% house fly larvae meal or 10% fish meal supplementation produced significantly heavier carcasses and breast muscle portions than the chicks that received the commercial maize: soya oil cake meal. No treatment differences were found regarding breast and thigh muscle colour or pH. This study showed that house fly larvae meal can be regarded as a safe protein source that can be used to replace other protein sources and that has the ability to promote broiler performance without having any detrimental effects on carcass characteristics.
AFRIKAANSE OPSOMMING: Die doel van die studie was om die effek van Musca domestica (gewone huisvlieg) larwe meel, as ‘n protein bron, in braaikuikens te evalueer. Dit was gedoen deur die nutrient waarde van huisvlieg larwe meel saam met die totale spysvertering verteerbaarheid, moontlike toksiesiteit en karkas-eienskappe van braai kuikens te evalueer. Laboratoruim analiese toon dat huisvlieg larwe meel 20.10 MJ/kg bruto energie, 60.38% ru- protein, 14.08% ru- vet en 10.68% as bevat en huisvlieg papie meel 20.42 MJ/kg bruto energie, 76.23% ru- protein, 14.39% ru- vet en 7.73% as bevat. Huisvlieg papie meel stem die meeste ooreen met die idiale amino suur profiel soos wat benodig word deur braaikuikens en dit het ‘n arginien tot lisien verhouding wat die meeste ooreenstem met die idiale amino suur profiel in vergelyking met huis vlieg larwe meel. Die essensiele vet suur, linolien suur, was geanaliseer teen vlakke van 26.25- en 36.27% van die totale vette onderskeidelik vir huisvlieg larwe- en papie meel. Huisvlieg larwe meel vervanging het nie spiermaag erosie of enige ander toksiese effekte te veroorsaak nie. Resultate het getoon dat huisvlieg papie meel, in vergelyking met larwe meel, het ‘n hoër totale spysvertering verteerbaarheid vir meeste van die nutrient. Die huisvlieg larwe meel het ‘n totale ru- protein spysvertering verteerbaarheid van 69% en die van papie meel van 79%. Beide larwe en papie meel het hoë amino suur spysvertering verteerbaarheid. Larwe meel en papie meel het skynbare metaboliseerbare energie waardes van 14.23MJ/kg en 15.15%MJ/kg onderskeidelik. Die larwe meel het ‘n ru-vet en ru- vesel spysvertering verteerbaarheid van 94% en 62% onderskeidelik, waar die papies ‘n ru-vet en ru- vesel spysvertering verteerbaarheid van onderskeidelik 98% en 58% het. Huisvlieg larwe meel vervanging in ‘n drie fase voer stelsel het getoon om die gemiddelde braaikuiken lewende gewigte by slag, totale voer iname, sowel as die gemiddelde daaglikse toename te verhoog waneer dit vergelyk word met ‘n kommersiele mielie- soya olie koek dieet. Geen mekwaardige verskille was waargeneem toe die 10% larwe meel dieet direk met die 10% vismeel diet vergelyk was rakende enige produksie einskappe gemeet nie. Die 25% larwe meel dieet het merkwaardig beter gemiddelde braaikuiken lewende gewigte by slag, totale voer iname, sowel as die gemiddelde daaglikse toename getoon wanneer vergelyk word met die 25% vismeel dieet gedurende die verskeie groei fases. Karkas eienskappe van die 10% larwe meel, 10% vismeel en die kommersiele diete was gevergelyk. Kuikens wat 10% larwe meel en 10% vismeel in die diete ontvang het, het swaarder karkasse gelewer met swaarder borsie massas wanneer vergelyk word met die kommersiele mielie- soya olie koek dieet. Geen behandelings verskille was gevind rakende die borsie- en dy spier kleure of pH nie. Die studie toon dat huisvlieg larwe meel as ‘n veillige protein bron kan beskou word, wat gebruik kan word om ander protein bronne te vervang. Huisvlieg larwe meel het ook die vermoë om braaikuiken produksie te verhoog sonder om enige negitiewe effekte rakende die karkas eienskappe te toon nie.

One of the major problems facing aquaculture in Ghana is the non-availability of quality and affordable fish feeds. The present study investigated the nutritional suitability and cost-effectiveness of some Ghanaian oilseed by-products, soybean meal (Glycine spp), cottonseed meal (Gossypium spp), groundnut cake (Arachis hypogaea L.) and groundnut husk, as alternative protein sources to fishmeal (FM) in the diet of Nile tilapia (Oreochromis niloticus L.). The oilseed meals were used individually, as mixtures, as mixtures enriched with methionine and mixtures detoxified by heat processing (autoclaving) and/or addition of supplements (viz. phytase and ferrous sulphate) intended to reduce levels of the most important antinutritional factors (ANFs). Diets, containing the oilseed meals at inclusion levels from 25% to 75% dietary protein, were formulated to be isonitrogenous (320 g.kg-1), isolipidic (100 g.kg-1) and isoenergetic (18 KJ.g-1) and fed to juvenile Nile tilapia at 4-10% of their body weight for a period of eight weeks. Proximate analysis showed that soybean meal (SBM), cottonseed meal (CSM), groundnut cake (GNC) and groundnut husk (GNH) had 500.3, 441.4, 430.5 and 205.6 g.kg-1 crude protein, 38.2, 89.5, 12.8 and 89.2 g.kg-1 crude fibre and 20.19, 19.61, 23.17 and 22.18 kJ.g-1 gross energy respectively. Generally the oilseed meals had good essential amino acid (EAA) profiles with the exception of GNH. The EAA profile of SBM compared very well with FM but methionine and threonine were low (0.73 and 1.50 % of protein respectively) and the same was true for CSM and GNC with even lower levels. Analyzed ANFs in SBM, CSM, GNC and GNH were 17.54, 31.64, 14.86 and 3.99 g.kg-1 phytic acid, 14.09, 1.24 and 2.34 g.kg-1 trypsin inhibitors and 5.80, 6.50, 8.01 and 10.08 g.kg-1 saponin respectively and in CSM 5.6 g.kg-1 gossypol. Nutrient digestibility of these oilseed proteins suggested that Nile tilapia may be able to utilize SBM, CSM and GNC efficiently as dietary protein sources due to high apparent protein digestibility of 94.50%, 84.93% and 90.01% respectively. However, GNH may not be suitable because of very low apparent protein digestibility (27.67%). These protein sources when used individually were shown to cause depressed growth and feed efficiency when substituting more than 50% of the FM protein in diets. This may be attributed to high levels of ANFs, high fibre content and poor EAA profile. However, the use of mixtures of these meals was found to be marginally more effective than that of single sources. This may have been as a result of lower levels of ANFs and improvement in essential amino acid profile due to mixing. Supplementing the mixtures with methionine led to improvement in feed utilization but without significantly improving the nutritive value compared with FM. Heat processing was effective in reducing heat labile trypsin inhibitors in SBM, CSM and GNC by almost 80%, but not phytic acid and saponins, which remained virtually unaffected. Use of meals detoxified by heat processing with/without supplements at 50% inclusion improved growth and feed utilization compared to the unprocessed meals and performance was generally not significantly different from FM. Cost effectiveness analysis revealed that diets containing single feedstuffs or mixtures, particularly those containing equal proportions of oilseed meals and higher proportion of CSM replacing between 50% - 75% FM protein, were more profitable than FM diet. Similarly, the use of heat processed meals at 50% replacement of FM protein yielded greater profit than all other diets including the FM diet. However, essential amino acid supplementation of the meals was less profitable compared to the control. Generally, fish fed diets with oilseed meals would take longer to attain harvest size compared with FM and this could lead to an increase in production costs or a decrease in the number of production cycles which could be achieved within a year. It can be concluded that there is nutritional and economic justification for using SBM, CSM and GNC as partial replacement for FM in diets of Nile tilapia. Based on growth performance, nutrient utilization and economic benefits the diet with heat processed oilseed meal mixtures (containing equal proportions of 16.67% each) at 50% inclusion has the best prospects for replacing FM protein in diets of O. niloticus.

Master of Science
Department of Animal Sciences and Industry
Teresa L. Slough
Teresa L. Slough
There is increasing interest in the use of point-of-care glucometers to monitor glucose concentrations in horses with metabolic disorders. The first study reported herein compared equine glucose concentrations obtained by a handheld glucometer using whole blood or plasma, a YSI 2300 bench top glucose analyzer using whole blood or plasma, and a SEVEN continuous glucose monitoring (CGM) device that measured glucose in interstitial fluid to readings obtained by a standard laboratory glucose analyzer utilizing plasma. In addition, glucose concentrations obtained by the CGM were compared to those obtained by the handheld glucometer using whole blood or plasma. Post-prandial increases and decreases in glucose concentrations were detected utilizing all glucometers tested. When glucose measurements obtained with the CGM in interstitial fluid were compared to glucose measured using the handheld glucometer in plasma or whole blood, glucose measurements from plasma had better reproducibility. Although the CGM could be a useful instrument for collecting nearly continuous data for the researcher and clinician, there are technical difficulties related to the CGM that must first be overcome. The second study was designed to compare the effects of consuming a twice-daily meal of sweet feed (SF) to ad libitum access to a molasses-based block (BL) supplement on patterns of interstitial glucose concentrations in horses. A novelty effect of the BL was observed, in which horses consumed increased quantities in the first 12 h. Treatments had no effect on intake of forage in this study. The range and means of glucose values were similar between treatments, and significant glucose responses to treatments had lag times that were indirectly similar, even though molasses intake was greater for horses on BL. Variability between horses was noted in quantity of BL consumed as well as timing and magnitude of glucose responses. Based on the results of this experiment, there does not appear to be a clear advantage to either treatment, SF or BL, in attenuating post-prandial glucose increases or in minimizing glucose fluctuations in the horse.

Three experiments were conducted to study the sensitivity of the pH-stat (in vitro) method in the prediction of true digestibility (TD), as measured by amount of base added, of plant proteins, either alone or in the presence of specific additives (nitrogen-free mixture, vitamin mixture and/or mineral mixture) as part of a complete diet of plant proteins that had been subjected to various levels and forms of heating. The in vitro TD values were then compared with TD values obtained in. vivo (Wistar rats). In experiment 1, the effect of temperature (dry-heating at 80, 100, 120, 150, 180 and 240° C or autoclaving at 121° C) and time (30, 60, 120 and 240 minutes) of heat application on in vitro base consumption (BC) was measured in 3 grains (wheat, barley and sorghum) and whole defatted soybeans. The largest increase in BC measured by the pH-stat method was that of soybeans in response to 30 minutes of autoclaving. Dry heating had various effects on the BC by soybeans, depending upon temperature and time of application, but none of the treatments was as beneficial as autoclaving. Mild, dry-heating of grains at 80-120° C improved BC slightly. The improvement was most marked for wheat. Both dry-heating of grain at temperatures above 120° C and autoclaving reduced the BC significantly for all durations. In experiment 2, the effect of inclusion of non-protein dietary components (minerals, vitamins and a nitrogen-free mixture, singly and in combination) on in. vitro BC measured by the pH-stat method of wheat and fat-extracted soybeans (both proteins in the raw and autoclaved forms) was monitored. For the wheat treatments, the inclusion of a mineral mixture significantly (p<0.001>) increased digestibility. This effect was greatest with autoclaved wheat. It was concluded that, in general, the presence of minerals increased the rate of hydrolysis. With raw soybeans, the distinction between treatments was less well-defined. The treatments containing vitamin or nitrogen-free and mineral combination mixtures were digested to a significantly greater extent than the raw soybeans alone. With autoclaved soybeans, additives had no effect. This lack of response to additives may have been due to the rather large amount of base required by the autoclaved soybean protein alone. In experiment 3, a series of rat-feeding trials were conducted in conjunction with in. vitro digestions. Diets were fed to groups of Wistar rats to determine TD, Biological Value (BV), and Net Protein Utilization (NPU) in vivo. Although BV was measured it was not relevant for this work. Concurrently, the same diets were tested for in. vitro TD by the pH-stat method. Specific regression equations were developed for each protein-type tested, after it was determined that a much lower correlation coefficient was obtained when one general equation was utilized. The newly-developed equations followed the format y = a + bx, where y = TD (as a part of one), a = the y-intercept, b = slope of the function and x = ml 0.10N NaOH added during the 10-minute digestion. Regression equations, correlation coefficients (r) and standard errors for each regression (s) between in. vitro and in vivo true digestibility of proteins were as follows; Soybean, soybean (autoclaved), soybean/wheat combinations (n = 6) r = 0.93 TD = 0.7868 + 0.2175x s = 0.018 Sorghum (raw, autoclaved, 90° C, 120° C, 180° C dry-heated, steamed) (n = 6) r = 0.92 TD = 0.4575 + 1.8841x a = 0.058 Alfalfa pellets/hay in combination with either wheat or barley (n = 13) r = 0.91 TD = 0.3446 + 1.0356x s = 0.046Alfalfa hay and barley combinations (n = 5) r = 0.96 TD = 0.2360 + 1.3194x s = 0.048 Grains (19 barleys, 10 triticales, 6 sorghums, and 2 wheats) (n = 37) r = 0.74 TD = 0.7419 + 0.4759x s = 0.044 In general, it can be stated that the pH-stat method is a useful method for screening proteins for the effect of various treatments on digestibility. Damage due to abnormally severe processing conditions (i.e. heating) is readily detected by the pH-stat technique as indicated by a decrease in the amount of base consumed during enzymatic hydrolysis.
Land and Food Systems, Faculty of
Graduate

Thesis (MScAgric)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: The objective of this study was to evaluate the use of Musca domestica (common house fly) larvae meal, as protein source, for broiler production. This was done by investigating the nutritive value of house fly larvae meal together with its total tract digestibility, potential toxicity and carcass characteristics of the broilers supplemented with house fly larvae meal. The proximate analysis of house fly larvae meal show that it contained, on a dry matter basis, a gross energy value of 20.10 MJ/kg, 60.38% crude protein, 14.08% crude fat and 10.68% ash and that the house fly pupae contained a gross energy of 20.42 MJ/kg, 76.23% crude protein, 14.39% crude fat and 7.73% ash. House fly pupae meal had the closest match of amino acid profile when compared with the ideal amino acid profile required by broilers and it has arginine relative to the lysine content closer to the ideal amino acid profile than the house fly larvae meal. The essential fatty acid, linoleic acid, was found at levels of 26.25 and 36.27% of the total fats for the house fly larvae and pupae meal respectively. House fly larvae meal supplementation did not induce gizzard erosion or showed toxicity (regarding the gastro intestinal tract, immune system and organ stress) in broilers. Results revealed that house fly pupae meal had higher total tract digestibilities for most nutrients than of the house fly larvae meal. House fly larvae meal had a crude protein total tract digestibility of 69% and that of pupae meal was 79%. Both larvae and pupae meal had high amino acid total tract digestibilities of all the amino acids analysed. The house fly larvae and pupae meal had an apparent metabolizable energy (AME) value of 14.23MJ/kg and 15.15MJ/kg respectively. The larvae meal total tract crude fat and crude fibre digestibilities were 94% and 62% respectively. The pupae meal total tract crude fat and crude fibre digestibilities were 98% and 58% respectively. House fly larvae meal supplementation in a three phase feeding system significantly increased average broiler live weights at slaughter, total feed intake, cumulative feed intake as well as average daily gain (ADG) when compared to commercial maize: soya oil cake meal diet. In direct comparison of larvae inclusion levels with fishmeal in isonitrogenous and isoenergetic diet, no significant differences were observed between a 10% house fly larvae and a 10% fish meal diets regarding performance characteristic. The 25% house fly larvae meal diet yielded significantly better average broiler live weights at slaughter, total feed intake, cumulative feed intake (from the second week until slaughter) as well as average daily gain when compared to the 25% fish meal diet in the growth phases. Carcass characteristics of the 10% larvae, 10% fishmeal and commercial diets were compared. Chicks that received either the 10% house fly larvae meal or 10% fish meal supplementation produced significantly heavier carcasses and breast muscle portions than the chicks that received the commercial maize: soya oil cake meal. No treatment differences were found regarding breast and thigh muscle colour or pH. This study showed that house fly larvae meal can be regarded as a safe protein source that can be used to replace other protein sources and that has the ability to promote broiler performance without having any detrimental effects on carcass characteristics.
AFRIKAANSE OPSOMMING: Die evaluasie van Musca domestica (gewone huisvlieg) larwe meel as ‘n proteien bron vir braaikuiken produksie Die doel van die studie was om die effek van Musca domestica (gewone huisvlieg) larwe meel, as ‘n protein bron, in braaikuikens te evalueer. Dit was gedoen deur die nutrient waarde van huisvlieg larwe meel saam met die totale spysvertering verteerbaarheid, moontlike toksiesiteit en karkas-eienskappe van braai kuikens te evalueer. Laboratoruim analiese toon dat huisvlieg larwe meel 20.10 MJ/kg bruto energie, 60.38% ru- protein, 14.08% ru- vet en 10.68% as bevat en huisvlieg papie meel 20.42 MJ/kg bruto energie, 76.23% ru- protein, 14.39% ru- vet en 7.73% as bevat. Huisvlieg papie meel stem die meeste ooreen met die idiale amino suur profiel soos wat benodig word deur braaikuikens en dit het ‘n arginien tot lisien verhouding wat die meeste ooreenstem met die idiale amino suur profiel in vergelyking met huis vlieg larwe meel. Die essensiele vet suur, linolien suur, was geanaliseer teen vlakke van 26.25- en 36.27% van die totale vette onderskeidelik vir huisvlieg larwe- en papie meel. Huisvlieg larwe meel vervanging het nie spiermaag erosie of enige ander toksiese effekte te veroorsaak nie. Resultate het getoon dat huisvlieg papie meel, in vergelyking met larwe meel, het ‘n hoër totale spysvertering verteerbaarheid vir meeste van die nutrient. Die huisvlieg larwe meel het ‘n totale ru- protein spysvertering verteerbaarheid van 69% en die van papie meel van 79%. Beide larwe en papie meel het hoë amino suur spysvertering verteerbaarheid. Larwe meel en papie meel het skynbare metaboliseerbare energie waardes van 14.23MJ/kg en 15.15%MJ/kg onderskeidelik. Die larwe meel het ‘n ru-vet en ru- vesel spysvertering verteerbaarheid van 94% en 62% onderskeidelik, waar die papies ‘n ru-vet en ru- vesel spysvertering verteerbaarheid van onderskeidelik 98% en 58% het. Huisvlieg larwe meel vervanging in ‘n drie fase voer stelsel het getoon om die gemiddelde braaikuiken lewende gewigte by slag, totale voer iname, sowel as die gemiddelde daaglikse toename te verhoog waneer dit vergelyk word met ‘n kommersiele mielie- soya olie koek dieet. Geen mekwaardige verskille was waargeneem toe die 10% larwe meel dieet direk met die 10% vismeel diet vergelyk was rakende enige produksie einskappe gemeet nie. Die 25% larwe meel dieet het merkwaardig beter gemiddelde braaikuiken lewende gewigte by slag, totale voer iname, sowel as die gemiddelde daaglikse toename getoon wanneer vergelyk word met die 25% vismeel dieet gedurende die verskeie groei fases. Karkas eienskappe van die 10% larwe meel, 10% vismeel en die kommersiele diete was gevergelyk. Kuikens wat 10% larwe meel en 10% vismeel in die diete ontvang het, het swaarder karkasse gelewer met swaarder borsie massas wanneer vergelyk word met die kommersiele mielie- soya olie koek dieet. Geen behandelings verskille was gevind rakende die borsie- en dy spier kleure of pH nie. Die studie toon dat huisvlieg larwe meel as ‘n veillige protein bron kan beskou word, wat gebruik kan word om ander protein bronne te vervang. Huisvlieg larwe meel het ook die vermoë om braaikuiken produksie te verhoog sonder om enige negitiewe effekte rakende die karkas eienskappe te toon nie.

La present tesi ha servit per avaluar estratègies per tal de redissenyar els sistemes d’engreix intensiu de vedells, amb l’objectiu de millorar-ne els resultats econòmics i disminuir-ne l’impacte mediambiental. A més, se n’ha determinat el vincle amb la microbiota ruminal, fent èmfasi en el concepte de rusticitat. Les estratègies testades van ser: la reducció del contingut de proteïna bruta de la dieta del 14 % al 12 % (sobre matèria seca); la substitució de la palla de cereal per un farratge de més qualitat (fenolatge de civada o de veça); i la millora de l’eficiència alimentària dels animals. Es va observar que les tres estratègies estudiades tenen efectes sobre els resultats productius, la ingestió d’aliment, les característiques de la fermentació ruminal i la composició i interaccions de la microbiota ruminal; concloent que són estratègies viables per tal de redissenyar el sistema d’engreix intensiu de vedells.
En la presente tesis se evaluaron estrategias para rediseñar los sistemas de engorde intensivo de terneros, con el objetivo de mejorar sus resultados económicos y disminuir su impacto medioambiental. Además, se determinó su vínculo con la microbiota ruminal, haciendo hincapié en el concepto de robustez. Las estrategias testadas fueron: la reducción del contenido de proteína bruta de la dieta del 14 % al 12 % (sobre materia seca); la substitución de la paja de cereal por un forraje de más calidad (henolaje de avena o veza); y la mejora de la eficiencia alimentaria de los animales. Se observó que las tres estrategias testadas tenían efectos sobre los resultados productivos, la ingestión de alimento, las características de la fermentación ruminal y la composición e interacciones de la microbiota ruminal, concluyendo que son estrategias viables para rediseñar el sistema de engorde intensivo de terneros.
The present thesis aimed at identifying and assessing strategies to redesign beef cattle intensive fattening systems in order to increase their profitability and decrease their environmental burden. Moreover, the potential role of ruminal microbiota in the outcome of the tested strategies was evaluated, focusing on their link with ruminal microbiota robustness. The strategies tested were: the reduction of dietary crude protein content from 14 % to 12 % (on a dry matter basis); the replacement of cereal straw by a quality forage (oats or vetch haylage); and the improvement of animals’ feed efficiency. It was observed that the three studied strategies had an impact on performance, feed intake, ruminal fermentation parameters and ruminal microbiota composition and interactions, concluding that they are feasible options to redesign intensive beef cattle production.

Thesis (MScAgric)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: The goat is a significant domestic animal throughout the world today. With an estimated world goat population of 590 million goats in 1991 (FAO, 1991 as citied by Haenlein, 1996) it is impossible to consider the goat as insignificant. The need for milk, and it seems particularly goat’s milk, is obvious if one considers the increase in dairy goat populations over the past 20 years. Across the globe the dairy goat population has increased by 52% while in developing and developed countries, there has been an increase of 56% and 17%, respectively (Haenlein, 2000). The goat dairy industry in South Africa is still very underdeveloped, yet it holds tremendous potential for the entrepreneur willing to take the risk and do the job correctly. With the present South African financial situation the opportunities that exist for exporting value added products to countries with stronger currencies is a market with extraordinary potential. In New Zealand, the national herd consists of approximately 16000 dairy goats and 90% of the milk produced is turned to powdered milk and then exported to the East, a valuable source of foreign currency. In South Africa, the same potential exists and with some vision and hard work the dairy goat industry can make a valuable contribution to generating foreign currency. Research into the protein requirements and particularly protein degradability requirements of dairy goats is scarce, yet in recent years there has been an increased interest in the effect of protein supplementation to lactating animals (Mishra & Rai, 1996). In the work of Mishra & Rai (1996) there were benefits obtained from the use of different rumen degradable proteins for lactating dairy goat does. The does on the highly degradable protein diet had a better feed intake while the does on the low degradable protein diet gave a higher milk production. Other research on this field of study has also delivered positive results with more than one species of lactating animal that had increased levels of UDP in the diet (Robinson et al., 1991 and Christensen et al., 1993). Loerch et al. (1995) suggested that improved production by making use of rumen undegradable proteins would have no effect if crude protein were not a limiting factor in production. Pailan & Kaur (1995) and Mishra & Rai (1996) did research on lowered CP levels with increased UDP levels in lactating dairy does. They used of three diets, with the one having a 20% lower CP value but an increased level of UDP (40-45% of total CP). From this work it was concluded that a decreased CP level and an increased level of UDP is able to sustain production when compared with diets with a higher CP value. The current study consists of two trials. In the first trial the effect of weaning age and dietary protein degradability on the growth of Saanen kids was investigated. In the second trial the effect of dietary protein degradability on the production of lactating Saanen does was investigated. Fifty-eight Saanen kids were divided into groups to determine the effect of weaning age (42 vs. 70 days) on animal performance. Within the weaning day treatments, the kids were again divided into two dietary treatments. One group received a low UDP creep diet (LC) and the other a high UDP creep diet (HC). The two creep diets were formulated with rumen degradable: undegradable protein (RDP : UDP) ratios of 70:30 and 60: 40, referred to as LC and HC, respectively. However, the results from the degradability trial indicated no difference in RDP: UDP ratios for the low and high creep (72:28 and 73:27 respectively) diets. At 15.66 ± 3.09 kg the kids were taken off the creep diet and put on the growth diet. At this transition, the kids in each of the 4 established treatments were again randomly divided into two dietary treatments, a high or a low UDP growth diet, resulting in a total of eight treatments for the trial. The two growth diets were formulated with RDP: UDP ratios of 70:30 and 60:40, referred to as low growth (LG) and high growth (HG) respectively. Results from the degradability trial indicated RDP: UDP ratios for the LG and HG of 73:27 and 68:32 respectively. The growth trial was conducted over 140 days and feed intake, bodyweight change and feed conversion efficiency were compared for each of the 8 treatments. From the trial with the Saanen kids it was concluded that weaning dairy goat kids at 42 days of age when feed intake was 240 g/day resulted in similar growth rates when compared with weaning at 70 days. The two creep diets did not differ in RDP: UDP ratios and thus no conclusion can be made regarding the influence of the creep diets on the growth of Saanen kids from 20 to 80 days of age. The two growth diets did in fact differ from one another, in terms of RDP: UDP however, protein degradability had no influence on the performance of the Saanen kids from 80 to 140 days of age. Twenty-one lactating Saanen does were randomly assigned to one of three experimental diets. The treatments had two RDP: UDP ratios and two crude protein (CP) levels. Treatments were formulated to be 1) RDP: UDP = 70:30, CP = 20 % 2) RDP: UDP = 62:38, CP = 20% and 3) RDP: UDP = 62:38, CP = 18.3%. In the production trial the does were milked for 120 days, during which milk yield, milk composition, bodyweight change, feed intake and feed conversion efficiency were compared between the treatments. In the digestibility and nitrogen metabolism trial, 18 does varying from 84 to 110 days in lactation, were used to compare the experimental diets. Furthermore, the experimental diets were compared in a degradability and rate of passage trial using cannulated Dohne merino wethers. Results from the degradability trial indicated that the low UDP, low protein high UDP and high UDP diets had RDP: UDP ratios of 82:18, 78:22 and 79:21 respectively, and that the dietary protein degradability did not differ significantly between diets. Results from the production trial indicated that there was a significant difference in feed intake, dry matter (DM) intake and bodyweight. The does on the low UDP diet had significantly higher feed intakes and DM intakes and were significantly heavier at the end of the trial period. As the diets didn’t differ in protein degradability other factors must have influenced the intakes between diets. Palatability may have influenced feed and DM intake, as the low protein high UDP and high UDP diets both contained higher levels of fishmeal. No significant differences in milk production, milk composition or milk production efficiency were observed. Besides the fact that the diets did not differ in effective protein degradability, large variations in milk production between animals and low numbers of animals per treatment limited the ability to measure a difference between the treatments. Results from the digestibility trial varied between diets with the low UDP diet having a significantly lower digestibility overall than the other two diets. Reasons for the difference in digestibility could be due to the difference in rate of passage (low UDP = 0.064/hour versus the 0.044- 0.045/hour of the low protein and high UDP diets respectively) and the high ADF value of the low UDP diet. Because no difference in effective protein degradability existed between the diets it is not possible to make an accurate conclusion on whether or not the dietary protein degradability had an influence on production parameters tested in this trial.
AFRIKAANSE OPSOMMING: Huidiglik is die bok ‘n belangrike gedomestikeerde dier dwarsoor die wereld. Aangesien die wereldwye bokpopulasie in 1991 op 590 miljoen geraam is (FAO, soos aangehaal deur Haenlein, 1996), is dit onmoontlik om die bok as onbelangrik te beskou. Die behoefte aan melk, en dan veral bokmelk, is duidelik as mens die toename in bokpopulasies oor die afgelope 20 jaar in ag neem. Wereldwyd het die melkbokpopulasie met 52% toegeneem, terwyl dit in ontwikkelende en ontwikkelde lande met 56% en 17% onderskeidelik, toegeneem het (Haenlein, 2000). Ten spyte van die feit dat die bokmelk-industrie in Suid-Afrika nog baie onderontwikkel is, is daar geweldige potensiaal vir die entrepeneur wat bereid is om ‘n risiko te loop en die taak korrek aan te pak. Binne die huidige Suid-Afrikaanse finansiele situasie bestaan daar veral geleenthede om waardetoegevoegde produkte na lande waarvan die wisselkoers sterker is, uit te voer. In Nieu Zeeland is die nasionale kudde ongeveer 16000 melkbokke en 90% van die geproduseerde melk word verwerk na poeiermelk en uitgevoer na die Ooste. In Suid-Afrika bestaan dieselfde potensiaal en met die korrekte visie en harde werk kan die melkbok-industrie ‘n belangrike bydra lewer om buitelandse valuta te verdien. Alhoewel navorsing aangaande die proteien-degradeerbaarheidsbehoeftes van melkbokke skaars is, bestaan daar die afgelope paar jaar ‘n toenemende belangstelling in die effek van proteien supplementering aan lakterende diere (Mishra & Rai, 1996). In die werk van Mishra & Rai (1996) is die voordele om verskillende rumen degraderende proteTenvlakke in lakterende melkbokke te gebruik, aangetoon. Ooie op ‘n hoogs degradeerbare prote'fen-dieet het beter voerinnames getoon, terwyl die ooie op ’n laag degradeerbare prote'fen-dieet hoer melkproduksies gelewer het. Navorsing van hierdie aard op ander lakterende spesies het ook positiewe resultate met ‘n toename in verbyvloeiprote'ien in die dieet gelewer (Robinson et al., 1991 en Christensen et al., 1993). Loerch et al. (1995) het voorgestel dat ‘n verbeterde produksie, deur gebruik te maak van verbyvloeiprote'fn, geen effek sal he as ruprote'fen (RP) nie ‘n beperkende faktor i.t.v produksie is nie. Beide Pailan & Kaur (1995) & Mishra en Rai (1996) het navorsing gedoen op die invloed van verlaagde RP-vlakke en verhoogde nie-degradeerbare protein (NDP) vlakke in die diete van lakterende melkooie. Daar is gebruik gemaak van drie diete, waarvan die een dieet ‘n 20% laer RPinhoud, maar ‘n verhoodge NDP-vlak (40-45% van totale RP) gehad het. Vanuit hierdie werk is die gevolgtrekking gemaak dat ‘n verlaging in RP-vlak en ‘n verhoging in NDP-vlak dieselfde produksie kan onderhou, soos met ‘n hoer RP-inhoud. Die huidige navorsing bestaan uit twee proewe. In die eerste proef is die effek van speenouderdom en dieet-prote'fen-degradeerbaardheid op die groei van Saanen-lammers ondersoek. In die tweede proef is die effek van dieet-proteien-degradeerbaardheid op die produksie van lakteerende Saanen melkbokke ondersoek. Agt-en-vyftig Saanen-lammers is verdeel in twee speenouderdom-behandelings, nl. ‘n 42 dae (42) en ‘n 70 dae (70) speenouderdom. Binne hierdie speenouderdom-behandelings is die lammers verder verdeel in twee dieet-behandelings. Die een groep het ‘n lae NDP kruiprantsoen (LK) en die ander ‘n hoe NDP kruiprantsoen (HK) ontvang. Die twee kruiprantsoene was geformuleer om rumen degradeerbare proteien (RDP): NDP verhoudings van 70:30 (LK) en 60:40 (HK) te bevat, maar die resultate van die degradeerbaarheidsproef het aangetoon RDP: NDP verhoudings van 77:23 (LK) en 78:22 (HK). Die lammers is vanaf die kruipdieet oorgeplaas op ‘n groeidieet by ‘n gemiddelde lewende massa van 15.99±3.09 kg. Tydens hierdie oorplasing is die lammers van die vier bestaande behandelings verdeel in ‘n verdere twee dieetbehandelings, nl. ‘n hoe of ‘n lae NDP groei-dieet (LG en HG onderskeidelik), met die gevolg dat ‘n totaal van agt behandelings in hierdie proef bestaan het. Die twee groeidiete is geformuleer met RDP: NDP verhoudings van 70: 30 (LG) en 60: 40 (HG) onderskeidelik, maar die resultate van die degradeerbaarheidsproef het aangetoon RDP: NDP verhoudings van 78:22 (LG) en 72:28 (HG). Die groeiproef is uitgevoer oor 140 dae en voerinname, verandering in liggaamsgewig en voeromsettingsdoeltreffendheid (VOD) is vergelyk tussen die agt behandelings. Uit die lammerproef is die gevolgtrekking gemaak dat boklammers wat op 42 dae gespeen is, wanneer voerinname 240g/dag is, soortgelyke resultate i.t.v. groeitempo lewer as lammers wat op 70 dae gespeen is. Die twee kruiprantsoene het nie van mekaar in RDP: NDP verskil nie en dus kan geen gevolgtrekking gemaak word omtrentdie invloed van dieet-protel'en-degradeerbaarheid op die groei van Saanen boklammers van 20 tot 80 dae ouderdom. Die twee groei diete het van mekaar verskil in RDP: NDP maar dieet-proteien-degradeerbaardheid het geen invloed op die groei van die Saanen boklammers van 80 tot 140 dae ouderdom gehad nie. Een-en-twintig lakterende Saanen-ooie is ewekansig in drie groepe. Die behandelings het twee RDP: NDP-verhoudings en twee ruprotei'en (RP) -peile ingesluit. Behandelings was 1) RDP: NDP = 70:30, RP = 20% 2) RDP: NDP = 62:38, RP = 20% en 3) RDP: NDP = 62:38, RP = 18.3%. Tydens hierdie produksieproef is die ooie vir 120 dae gemelk en die melkopbrengs, melksamestelling, verandering in liggaamsgewig, voerinname en VOD bepaal en vergelyk tussen behandelings. In die verterings- en stikstofmetabolismeproef is 18 ooie gebruik om die diete te vergelyk. Verder is die diete ook vergelyk in ‘n degraderings- en deurvloeitempoproef met gekannuleerde Dohne merino hamels. Dieet-proteien-degradeerbaardheid waardes verkry uit die degradeerbaarheidsproef het aangedui dat die bepaalde RDP: NDP verhoudings was 82:18, 78:22 en 79:21 vir die lae NDP, lae prote'fen hoe NDP en hoe NDP diete, en dat daar geen verskil in dieet-prote'fen-degradeerbaardheid was tussen die drie rantsoene. Resultate van die produksieproef dui daarop dat daar verskille in voerinname, droematerialinname, en liggaamsgewig tussen die drie rantsoene was. Die ooie op die laer NDP rantsoen het ‘n hoe voer en DM inname gehad en was swaarder na 120 dae in die proef as die ooie in die ander twee behandelings. Redes vir hierdie verskille is nie as gevolg van dieet-proteiendegradeerbaarheid nie. Die smaaklikheid kon dalk ‘n rol gespeel het omdat dat die twee hoe NDP rantsoene hoer vlakke van vismeel gehad het. Daar was geen verskil in melkproduksie, melksamestelling en melkproduksiedoeltreffenheid tussen die drie behandelings. Resultate van die verteringsproef het tussen die laer NDP-rantsoen en die ander twee rantsoene gevarieer. Die rede vir die verskil in verteerbaarheid mag wees a.g.v. verskillende deurvloeitempo’s (laer NDP = 0.064/uur teenoor 0.044 - 0.045/uur vir die laeproteien en hoe-proteienrantsoene) en die ADF waarde wat van die lae NDP rantsoen verskil het van die ander twee rantsoene. Omdat die resultate van die degradeerbaarheidsproef aangedui het dat daar geen verskil in dieet-proteiendegradeerbaardheid was nie is dit nie moontlik om ‘n gevolgtrekking te maak random die invloed van dieet-proteien-degradeerbaardheid op die produksie van lakterende Saanen melkbokke nie.

For two decades, multiple observations of nonparallel pancreatic secretion, wherein digestive enzyme proportions change rapidly following various digestive stimuli, have conflicted with the concept of exocrine pancreatic homogeneity and the exocytosis model of parallel synthesis, transport and secretion of proteins. Evidence of pancreatic heterogeneity is presented, potentially resolving this longstanding controversy. Correlation and regression analysis simultaneously demonstrated exocytosis and nonparallel secretion, suggesting the existence of multiple heterogeneous exocytotic pathways. Next, heterogeneous prestored pancreatic protein sources were directly demonstrated using double isotopic labelling; temporal and secretagogue-specific regulation of the heterogeneous secretory sources was uncovered. Finally, specific enzyme proportions were linked to the heterogeneous sources by densitometric measurements of electrophoretic gels of secreted proteins. Thus, it appears that differential secretion from heterogeneous sources of prestored secretory proteins containing unique proportions of digestive enzymes is the basis of regulated nonparallel secretion in the exocrine pancreas.

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Conselho Nacional de Desenvolvimento Científico e Tecnológic
Este trabalho foi desenvolvido a partir de três estudos. Assim, o objetivo do primeiro estudo foi identificar variáveis que afetam o consumo de concentrado (CC), e desenvolver equações para predizer o CC de bezerros leiteiros até os 64 dias de vida. O banco de dados foi composto pelos dados individuais de 189 bezerros de 8 experimentos, totalizando 6.426 observações diárias de consumo. A informação coletada dos estudos foram: peso corporal ao nascimento (PCi; kg), CC (kg/dia), consumo de leite ou sucedâneo (CL; L/dia), sexo (macho ou fêmea), raça (Holandês ou mestiço Holandês×Gir) e idade (dias). A correlação entre o CC e as variáveis quantitativas CL, PCi, PCi metabólico (PCi0,75) e idade foi estabelecida. Posteriormente, foi realizada uma avaliação gráfica do comportamento padrão dos dados; e um modelo exponencial foi escolhido. Os dados foram avaliados usando a técnica de meta-análise para estimar os efeitos fixos e os efeitos aleatórios associados aos experimentos através de modelos mistos não-lineares. A técnica de validação cruzada foi utilizada para estimar a acurácia e precisão das equações desenvolvidas, com base no quadrado médio do erro de predição (QMEP), coeficiente de correlação de concordância, que foi decomposto em acurácia (Cb) e precisão (ρ). De forma adicional, uma análise tipo “bootstrap” foi utilizada para estimar o viés associado a cada parâmetro das equações desenvolvidas. Uma correlação negativa entre CC e CL foi observada (r= -0,388), no entanto, idade apresentou uma correlação positiva com CC (r= 0.66). Não foi observado efeito do tipo de alimento líquido utilizado (leite ou sucedâneo) no desenvolvimento da equação. No entanto, foram ajustadas 2 equações, significantemente diferente para todos os parâmetros, para predizer o CC para bezerros consumindo menos que 5 (CC<5) ou mais que 5 (CC>5) litros/dia de leite ou sucedâneo: CC<5 = 0,1839±0,0581 × CL × exp((-0,0040±0,0011 × CL + 0,0333 ±0,0021 ) × (I- (6,0332 ±0,3583 × CL + 0,8302± (0,12 × CL); CC>5 = 0,1225±0,0005 × CL × exp((-0,0015±0,0001 × CL + 0,0217±0,0006) ×))) 0,5092 - (I- (1,9508 × CL + 3,5382± )))1,3140 ±0,1710 - (0,12 × CL); onde CC<5 e CC>5 = consumo predito de concentrado para bezerros que consomen menos de 5 ou mais de 5 litros/dia de leite ou sucedâneo, respectivamente (kg/dia); CL = consumo de leite ou sucedâneo (L/dia) e I = idade (dias). Estas equações apresentaram alta acurácia (Cb de 0,97 e 0,95 para CC<5 e CC>5, respectivamente) e o erro aleatório do QMEP foi de 99,8 e 99,9% para CC<5 e CC>5, respectivamente. A análise “bootstrap” indicou um baixo viés para todos os parâmetros estimados em ambas as equações. A precisão das equações foi moderada, com valores de r2 de 0,61 e 0,52 e valores de ρ de 0,78 e 0,72 para CC<5 e CC>5, respectivamente. Conclui-se que a utilização de leite ou sucedâneo como alimento líquido não afeta o CC, ou o desenvolvimento do CC ao longo do tempo, o qual aumenta exponencialmente de acordo com a idade do bezerro. O CC foi negativamente afetado pelo CL e, por esta razão, diferentes equações são necessárias para estimar o CC de acordo com o CL. O segundo estudo objetivou avaliar a influência de diferentes níveis de proteína não-degradável no rúmen (PNDR) sobre o consumo, desempenho, características de carcaça, balaço de N, desenvolvimento da glândula mamária e o status hormonal de novilhas Holandesas em diferentes estágios fisiológicos (EF). Foram utilizadas 16 novilhas pré-puberes (PRE), com peso corporal inicial de 106±7,6 kg e 4±0,46 meses de idade, bem como 16 novilhas púberes (PUB), com peso corporal inicial de 224±7,9 kg e 12±0,45 meses de idade. O experimento teve uma duração de 84 dias e foi conduzido segundo um delineamento inteiramente casualizado, segundo um esquema fatorial 4×2, com 4 níveis de PNDR na proteína total da dieta ((38, 44, 51 e 57%) e animais em duas idades diferentes (pré-puberes e púberes). Entre os dias 36 e 40 e os dias 78 e 82 os animais foram submetidos à ensaios de digestibilidade com coleta de alimentos, sobras e coletas “spot” de fezes e urina. No dia 0 (imediatamente antes do início do experimento) e dia 83 foram tomadas imagens de ultrassom na área lombar dos animais. Nos dias 0, 21, 42, 63 e 84 foram tomadas imagens de ultrassom da glândula mamaria. E, por fim, nos dias 0 e 84 foram tomadas amostras de sangue para estimar as concentrações séricas de progesterona, estrógeno, IGF-I e insulina. O EF afetou a digestibilidade aparente da MS, e novilhas PRE apresentaram menores valores. Novilhas PRE também apresentaram consumo preferencial por fibra em detergente neutro corrigida para cinzas e proteína (FDNcp) e atividade de seleção contra a proteína bruta (PB) maior que novilhas PUB. O ganho médio diário (GMD) e a retenção de N foram afetados pelo EF, e novilhas PRE apresentaram um GMD de 505 g/dia, enquanto novilhas PUB apresentaram um valor médio de 905 g/dia. Adicionalmente, estas variáveis foram afetadas pelo nível de PNDR, e maiores valores foram obtidos para o tratamento com 51% de PNDR. A análise de pixels na glândula mamária apontou efeito do EF, e novilhas PRE apresentaram maiores valores de pixel. As mensurações iniciais de progesterona sérica demonstraram que as novilhas PRE e PUB mantiveram seu EF durante o experimento. A concentração de IGF-I foi afetada somente pelo EF, e novilhas PUB apresentaram maiores valores. A concentração de insulina não foi afetada pelo EF, mas apresentou uma tendência de ser maior para os tratamentos com 51% de PNDR. Conclui-se que o nível dietético de 51% de PNDR é responsável por aumentar o desempenho de novilhas PRE e PUB. Adicionalmente, novilhas PRE tem menor habilidade de seleção, o que afeta, negativamente, a sua digestibilidade e desempenho. Finalmente, estes animais são mais propensos a ter uma maior proporção de gordura na glândula mamaria, mesmo sob moderadas taxas de crescimento. O terceiro estudo foi conduzido com o objetivo de avaliar de níveis crescentes de PNDR sobre o consumo, as digestibilidade parciais e total, a cinética e as características ruminais, bem como a utilização do N de novilhas leiteiras holandesas. Foram utilizadas 8 novilhas holandesas fistuladas no rúmen, com peso corporal inicial de 276±8,3, em delineamento em quadrado latino 4×4 duplo, com quatro níveis de PNDR na proteína dietética, como segue: 38% de PNDR (38PNDR); 44% de PNDR (44PNDR); 51% de PNDR (51PNDR) e 57% de PNDR (57PNDR). O experimento teve duração de 84 dias, subdivididos em 4 períodos experimentais de 21 dias (14 dias de adaptação + 7 dias de coletas). Foram realizadas 8 coletas “spot” de fezes, urina, conteúdo ruminal e digesta omasal, com intervalo de 8 horas entre cada coleta, como segue: no 15o dia as amostras foram coletadas as 0600h e 1500h; no 16o dia as amostras foram coletadas as 0000h, 0900h e 1800h; e no 17o dia as amostras foram coletadas as 0300h, 1200h e 2100h. No 19o dia foi realizado esvaziamento completo do rúmen 4 horas após a alimentação matutina e no 21o dia o esvaziamento foi realizado imediatamente antes da alimentação matutina. O consumo diário de MS, matéria orgânica (MO), PB, FDNcp e FDNcp potencialmente digestível (pdFDNcp) não foi afetado pelos níveis de PNDR. Adicionalmente, o consumo relativo (g/kg de peso corporal) de MS, PB e FDNcp, assim como o fluxo ruminal de MS, MO, PB, FDNcp pdFDNcp não foram afetados pelos níveis de PNDR. A digestibilidade total da MS, MO, PB, FDNcp e pdFDNcp, bem como as digestibilidade ruminal e intestinal da MS, MO, FDNcp e pdFDNcp não foram afetados pelos níveis de PNDR. No entanto, as digestibilidade ruminal e intestinal da PB apresentaram uma tendência de decréscimo de acordo com o aumento nos níveis de PNDR. Não foram observados efeitos dos níveis de PNDR sobre as taxas de ingestão, passagem e digestão, assim como sobre a concentração de ácidos graxos voláteis. O tratamento 38PNDR apresentou maior concentração de nitrogênio amoniacal ruminal em relação aos outros tratamentos. A excreção de nitrogênio urinário apresentou tendência de queda de acordo com o aumento nos níveis de PNDR. Adicionalmente, o nitrogênio retido apresentou tendência de aumento de acordo com o aumento nos níveis de PNDR e foi maior para os tratamentos 51PNDR e 57PNDR. A síntese de proteína bruta microbiana, a eficiência de síntese de proteína microbiana (PBmic) e a eficiência de uso do nitrogênio para síntese de proteína microbiana diminuíram de acordo com o aumento nos níveis de PNDR na dieta. O fluxo de PNDR aumentou, enquanto a quantidade de proteína degradável no rúmen decresceu de acordo com o aumento nos níveis de PNDR. Adicionalmente, o fluxo de proteína metabolizável apresentou tendência de aumento de acordo com o aumento nos níveis de PNDR e maiores valores foram observados para os tratamentos 51PNDR e 57PNDR. Conclui-se que a digestibilidade intestinal da PB é negativamente afetada pelos níveis de PNDR, o que é proporcionado pela redução no fluxo de PBmic, sendo que esta, provavelmente, digestibilidade intestinal da proteína maior que os alimentos. A excreção urinária de N diminui à medida que a PNDR dietética aumenta, o que é proporcionado pela queda nas perdas ruminais de nitrogênio na forma de amônia e pelo aumento na reciclagem de nitrogênio para o rúmen. A redução na excreção urinaria de nitrogênio, aliada ao aumento no fluxo de proteína metabolizável, o qual foi promovida pelo aumento no fluxo de PNDR ao intestino delgado, são determinantes para promover aumentos na retenção de nitrogênio, o que ocorreu nos tratamentos 51PNDR e 57PNDR.
This work was developed from three studies. Therefore, the objective of the first study was to identify variables that influence starter feed intake (SFI), and to develop equations to predict SFI in milk-fed dairy calves up to 64 days of age. The database was composed of individual data of 189 calves from 8 experiments, totaling 6,426 daily observations of intake. The information collected from the studies were: birth body weight (birth BW; kg), SFI (kg/day), fluid milk or milk replacer intake (MI; L/day), sex (male or female), breed (Holstein or Holstein×Gyr crossbred), and age (days). A correlation between SFI and the quantitative variables MI, birth BW, metabolic birth BW (birth BW 0.75), and age was established. Subsequently, data were graphed and based on a visual appraisal of the pattern of the data; an exponential function was chosen. The data were evaluated using a meta-analysis approach to estimate fixed and random effects of the experiments using nonlinear mixed coefficients statistical models. Cross-validation was used to estimate the accuracy and precision of the developed equations using the mean square error of prediction (MSEP), concordance correlation coefficient, which was decomposed into accuracy (Cb) and precision (ρ) parameters, and the coefficient of determination (r 2) as a proxy for precision. In addition, a bootstrap analysis was used to estimate the bias associated with each parameter of the developed equation structure. A negative correlation between SFI and MI was observed (r = –0.388), but age had a positive correlation with SFI (r =0.66). No effect of liquid feed source (milk or milk replacer) was observed in developing the equation. However, 2 equations, significantly different for all parameters, were fit to predict SFI for calves that consume less than 5 (SFI<5) or more than 5 (SFI>5) L/day of milk or milk replacer: SFI<5 = 0.1839±0.0581 ×MI×exp((-0.0040±0.0011× MI + 0.0333 ±0.0021) × (A- (6.0332 × MI + 0.8302±)))±0.35830.5092 - (0.12 × MI); CC>5 = 0.1225±0.0005 × MI × exp((-0.0015±0.0001 × MI + 0.0217±0.0006) × (A- (1.9508±0.1710 × MI + 3.5382±1.3140))) - (0.12 × MI); whereSFI<5 and SFI>5 = starter feed intake prediction for calves that consume less than 5 and more than 5 L/day of milk or milk replacer, respectively (kg/d); MI = milk or milk replacer intake (L/d) and A = age (days). These equations had high accuracy (Cb of 0.97 and 0.95, respectively) and the random errors of MSEP were 99.8 and 99.9% for SFI<5 and SFI>5 equations, respectively. Small biases were observed with the bootstrap analyses for all estimated parameters. The equations’ precision was moderate, with r 2 values of 0.61 and 0.52 and ρ values of 0.78 and 0.72 for SFI<5 and SFI>5, respectively. In conclusion, the use of milk or milk replacer as liquid feed did not affect SFI, or development of SFI over time, which increased exponentially with calf age. Starter feed intake was negatively affected by MI and, and for this reason, different equations are necessary to predict calf SFI according to MI. The second study aimed to evaluate the influence of different levels of rumen undegradable protein (RUP) on intake, performance, carcass characteristics, N balance, mammary gland development and hormonal status of Holstein heifers at different physiological stage (PS). Sixteen prepubertal (PRE) heifers with 106±7.6 kg of initial body weight and aged 4±0.46 months old, as well as, 16 pubertal (PUB) heifers with 224±7.9 kg of initial body weight and aged 12±0.45 months old were used. The experiment was carried out during 84 days following a complete randomized design, in a 4×2 factorial arrangement, with four levels of RUP in dietary protein (38, 44, 51, and 57%), and animals at two PS (prepubertal or pubertal). Between days 36 and 40 and between days 78 and 82 the animals were subjected to digestibility trials with collections of feeds, orts and spot collections of feces and urine. At days 0 (immediately before the beginning of the experiment) and 83 body ultrasound images were taken at the rib area. At days 0, 21, 42, 63 and 84 images of the mammary gland were taken via ultrasound. Finally, at days 0 and 84 blood samples were taken to estimate serum concentration of progesterone, estrogen, IGF-I and insulin. The PS affected the apparent digestibility of DM, and PRE heifers presented lower values. The PRE heifers also presented a preferential consumption for neutral detergent fiber corrected for ash and protein (NDFap) and sorting activity against CP greater than PUB heifers. The average daily gain (ADG) and N retention were affected by PS, and PRE heifers presented an ADG of 505 g/d, while PUB heifers presented an average value of 905 g/d. In addition, these variables were affected by RUP levels, where greater values were obtained for treatments with 51% of RUP. The analysis of pixels in mammary gland images pointed effects of PS, and PRE heifers presented greater pixels values. The initial and final measurements of serum progesterone demonstrated that PRE and PUB heifers kept their PS during the experiment. The IGF-I concentration was only affected by PS, and PUB heifers presented greater values. In addition, insulin was not affected by PS, but presented a tendency to be greater at treatments with 51% of RUP. In conclusion, the dietary level of 51% of RUP is responsible to increase the performance of PRE and PUB Holstein heifers. In addition, PRE heifers have lower sorting ability, what affected, negatively, their digestibility and performance. Finally, these animals are more likely to have greater fat proportion in the mammary gland, even under moderate rates of growth. The third study aimed to evaluate the influence of increasing levels of RUP on intake, total and partial digestibilities, rumen kinetics and characteristics, as well the N use of dairy Holstein heifers. Eight rumen-cannulated Holstein heifers, with an average initial body weight of 276±8.3 were used in a double 4×4 Latin Square design with four levels of RUP in the total dietary protein, as follows: 38% of RUP (38RUP); 44% of RUP (44RUP); 51% of RUP (51RUP) and 57% of RUP (57RUP). The experiment was carried out during 84 days subdivided into 4 experimental periods of 21 d (14 d for adaptation + 7 d for collections). Eight spot collections of feces, urine, ruminal content and omasal digesta were performed with 9 hours interval between each collection, as follows: on 15th d samples were collected at 0600 h and 1500 h; on 16th day samples were collected at 0000 h, 0900 h and 1800 h; on 17th d samples were collected at 0300 h, 1200 h and 2100 h. On 19th d a complete rumen evacuation was performed, 4 hours after the morning feeding and on 21st d immediately before morning feeding. Daily intake of DM, organic matter (OM), CP, NDFap and potential digestible NDFap (pdNDFap) were not affected by RUP levels. In addition, the relative intake (g/kg of body weight) of DM, CP and NDFap, as well as the ruminal outflow of DM, OM, CP, NDFap and pdNDFap were not affected by RUP levels. Total digestibility of DM, OM, CP, NDFap and pdNDFap, as well as ruminal and intestinal digestibilities of DM, OM, NDFap and pdNDFap were not affected by RUP levels. However, ruminal and intestinal digestibilities of CP presented a tendency to decrease according to RUP supply increase. Effects of RUP levels were not observed on the ingestion, passage and digestion rates, as well on the total volatile fatty acid concentration. Treatment 38RUP presented greater concentration of rumen ammonia nitrogen in relation to the other treatments. The urinary N excretion presented a tendency to decrease according to RUP supply increase. In addition, retained N presented a tendency to increase according to RUP levels and greater values were observed for treatments 51RUP and 57RUP. Microbial crude protein (CPmic) synthesis, microbial efficiency and the efficiency of use of N for microbial synthesis, decrease as the supplied RUP increases. Flow of RUP increased, while the amounts of rumen degradable protein decrease according to RUP supply increase. In addition, the flow of metabolizable protein presented a tendency to increase and greater values were observed for treatments 51RUP and 57RUP. In conclusion, the intestinal digestibility of CP is negatively affected by RUPvlevels, what is due to the reduction in the CPmic flow, which, probably, has greater intestinal digestibility than protein of feedstuffs. The urinary N excretion decrease according to RUP supply increase, what is due to the decrease in ruminal N losses as ammonia and the increase in N recycling. The reduction in the urinary N excretion allied to increases in the flow of metabolizable protein, which are promoted by increases in the flow of RUP to the small intestine, are determinant to promote increases in the retained N, which occurred for treatments 51RUP and 57RUP.

Attempts to improve upon the crude protein feeding system have strived to characterize feedstuffs with respect to ruminal protein degradability. In vitro an in situ procedures fall short of this goal by not accounting for ruminal turnover. Six lactating cows, fitted with ruminal and duodenal cannulae, were utilized for in vivo determination of protein degradability by employing a double-marker system. Treatments were corn silage-based diets supplemented with 2:1 soybean meal:fish meal nitrogen (SF) or 1:2 soybean meal:fish meal nitrogen (FS) at levels of 15. 9 and 16.0 percent protein. Ruminal cobalt ethylenediaminetetraacetic acid (CoEDTA) infusions marked liquid phase (LP) digesta and Yb-soaked hay was used as a solid phase (SP) marker. Duodenal digesta was separated into SP and LP at 3000xg. Least squares means of LP flows did not differ for total, precipitable protein, or microbial nitrogen, for SF and FS. Total solid phase flow of dry matter was higher for FS (9.06 kg/d) than for SF (7.97 kg/d), although intakes did not differ. Milk composition and yield did not differ for FS and SF. Average daily gain was 0.12 kg/d for SF and 1:26 kg/d for FS. Whole-tract digestibilties were not different although rumen digestibility of dry matter was 24.9% for FS and 35.7% for SF, and duodenal recovery of N was 93.8% for SF and 107.5% for FS. Inclusion of a higher level of fish meal in the diet increased the proportion of feed proteins delivered to the small intestine, increasing weight gain while having no effect on milk production.
Master of Science

Thesis (MScAgric)--University of Stellenbosch, 2000
ENGLISH ABSTRACT: A flock of 500 Hybro broiler breeders were employed to study the effect of different levels of protein and energy on production and body composition. The daily lysine intake of the birds were 900, 1050, 1200 and 1350 mg respectively, each fed in diets with a daily energy intake of 1800 and 2000 kJ ME to provide a 4 x 2 factorial design. Lysine was used as the reference amino acid in the experiment and all other amino acids were kept in a constant ratio in every experimental diet. The total production was divided into 3 periods of 13 weeks each (week 23 - 35; week 36 - 48 and week 49 - 61) to determine the effect of the treatments over time. Production was evaluated by hen day production; egg weight (g/egg); egg mass (g/day); fertility; hatchability; chicks/hen/week; feed conversion and day old chick weight. Hen day production was significantly (P < 0,05) lower at the high energy intake for period week 49 to 61. Energy and protein levels significantly increased egg weight. Effect of protein was consistent during all three periods of production. Egg mass output had a significant (P < 0,05) response to increasing levels of protein for the total period of production. The birds on the high energy diet produced a significant higher egg mass per hen during the first period of production (week 23 - 35). Hatchability was reduced (P < 0,05) by the higher energy intake for the total period of production and this effect was very significant (P < 0,01) during the final period of production. Similar to hen day production, the higher energy had a significant (P < 0,05) negative effect on the amount of chicks produced. The well-known correlation between egg weight and chick weight was confirmed with the regression equation: Chick weight = 10,5 + 1,22 x Egg weight. Both energy and protein had a significant (P < 0,01) positive effect on chick weight. The feed conversion was lower at increasing levels of amino acid intake (P < 0,01). Higher energy intake significantly (P < 0,05) increased hen weight and protein had a very significant effect during the first period of production (P < 0,01). The isotope dilution technique (tritiated water) was used to estimate the body composition of the breeders. This was done at 5 different periods (week 27, 35, 43, 52 and 61) of the production period to establish changes in requirements over time. Significant correlation were found between carcass moisture and waterspace (R2 = 0,76); fat % and carcass moisture (R2 = 0,78); protein % and waterspace (R2 = 0,35) and fat % and waterspace (R2 = 0,46). The regression equations obtained from these correlation were employed to determine excess energy and lysine consumed at different ages. Energy requirements were calculated according to the effective energy (EE) system and the conventional ME system. According to effective energy the lower energy intake was not sufficient and the maximum requirement was calculated to be 1942 kj EE/day. The metabolizable energy calculations indicated sufficient intakes at every treatment with the maximum requirement 1746 kj ME/day. The lysine requirement was found to be in excess of 1050 mg lysine per day. The recommendation for daily lysine intake is 1200 mg/day and the energy intake of breeders should be 1900 to 2000 kj ME/day from week 23 to 35 and can be reduced to 1800 kj ME/day in the final period of production.
AFRIKAANSE OPSOMMING: Om die effek van verskillende vlakke energie en proteïen op produksie en liggaamsamestelling te ondersoek is 'n trop van 500 Hybro braaikuiken teelouers gebruik. Die daaglikse lisien inname van die henne was onderskeidelik 900, 1050, 1200 en 1350 mg, wat elk by 'n daaglikse energie inname van 1800 en 2000 kJ ME verskaf is, in 'n 4 x 2 faktoriale ontwerp. Alle aminosure is in 'n konstante verhouding met die verwysings aminosuur lisien in die rantsoen ingesluit. Om te evalueer of daar veranderinge oor 'n tydperk plaasvind weens die verskillende behandelings is die produksie periode in drie periodes van 13 weke elk verdeel (week 23 - 35; week 36 - 48 en week 49 - 61). Die produksie standaarde wat gemeet is, is hen dag produksie, eiergewig (g/eier), eiermassa (g/dag), vrugbaarheid, uitbroeibaarheid, kuikens/hen/week, voeromset en dagoud kuikenmassa. Hen dag produksie was betekenisvol (P < 0,05) laer by die hoër energie innames in die laaste periode van 49 tot 61 weke. Energie en proteïen het eiergewig betekenisvol (P < 0,01) verhoog. Die effek van hoër vlakke proteïen was konstant in alle produksie periodes. Die daaglikse eiermassa (g/dag) het ook saam met stygende vlakke proteïen verhoog en hierdie effek was vir die totale periode van produksie. Energie het die eiermassa in die eerste periode van produksie (week 23 - 35) verhoog. Uitbroeibaarheid is verlaag (P < 0,05) vir die totale periode van produksie deur die hoër energie inname en die effek was selfs groter (P < 0,01) in die finale periode van produksie. In ooreenstemming met die hen dag produksie is die aantal kuikens geproduseer negatief beïnvloed deur die hoër energie inname (P < 0,05). Die korrelasie wat bestaan tussen eiermassa en kuikenmassa is bevestig deur die regressie: Kuikenmassa = 10,5 + 1,22 x Eiermassa. Energie en proteïen het kuikenmassa betekenisvol (P < 0,01) verhoog. Voeromset was laer by stygende vlakke van proteïen inname (P < 0,01). Die hoër energie inname het henmassa ook betekenisvol (P < 0,05) verhoog en proteïen het dieselfde effek slegs in die eerste periode van produksie gehad (P < 0,01). Die liggaamsamestelling van teelhenne is bepaal met behulp van die isotoop verdunnings tegniek (tritium water). Dit is bepaal op 5 verskillende stadiums in die produksie periode (week 27, 35, 43, 52 en 61) om die moontlike verandering in behoeftes oor tyd vas te stel. Betekenisvolle korrelasies is gevind tussen karkasvog en die waterspasie (RZ= 0,76); vet % en karkasvog (R2 = 0,78); proteïen % en waterspasie (R2 = 0,35) en vet % en waterspasie (R2 = 0,46). Die regressie vergelykings van hierdie korrelasies is gebruik om die hoevelheid surplus energie en lisien ingeneem te bepaal. Die" effective energy" sisteem en die konvensionele ME sisteem is gebruik in die bepaling van energie behoeftes. Volgens die " effective energy" was die energie inname nie voldoende by die laer energie innames nie en die maksimum behoefte is bereken as 1942 kJ EE/dag. Die maksimum energie behoefte volgens metaboliseerbare energie is bereken as 1746 kj ME/dag. Die lisien behoefte moet hoër as 1050 mg/dag wees. Die aanbeveling van die daaglikse lisien inname is 1200 mg/dag en die energie inname moet 1900 tot 2000 kj/dag wees tot 35 weke produksie en kan daarna verlaag word na 1800 kJ ME/dag.

Master of Science
Department of Animal Sciences and Industry
Jim Nelssen
Seven experiments using a total of 3,251 preweaned pigs, nursery pigs, and sows were used to determine the effects of: 1) supplemental vitamin D[subscript]3 on suckling and nursery pig growth, and maternal performance, and 2) high sulfate water, dietary zeolite and humic substance on nursery pig performance. Also, a web-based survey was developed to question pork producers and advisors of the swine industry on their knowledge of feed efficiency. Experiment 1 tested an oral dose of either; none, 40,000 or 80,000 IU vitamin D[subscript]3 given to pigs 24 to 48 h after farrowing. No differences in growth performance or bone mineralization were observed, but vitamin D[subscript]3 supplementation increased serum 25(OH)D[subscript]3 on d 10, 20, and 30, but returned to control values by d 52. Experiments 2 and 3 evaluated an oral dose of vitamin D[subscript]3 to pigs just before weaning, as well as added D[subscript]3 in nursery diets and in drinking water. There were no effects on growth performance; however, serum 25(OH)D[subscript]3 increased with all sources of vitamin D[subscript]3 supplementation. Experiment 4 evaluated if pigs had a preference to 1 of 3 dietary concentrations of vitamin D[subscript]3. Pigs ate less feed from diets containing very high levels of vitamin D[subscript]3 compared to commonly supplemented levels. Experiment 5 evaluated 3 levels of vitamin D[subscript]3 in sow diets. There were no effects on sow productivity, subsequent pig performance, or piglet bone ash content. However, increasing vitamin D[subscript]3 increased sow serum 25(OH)D[subscript]3, milk vitamin D, and pig serum 25(OH)D[subscript]3. Experiment 6 and 7 evaluated the effects of dietary zeolite and humic substances in nursery pigs drinking high sulfate water. Ultimately, pigs drinking high sulfate water had increased fecal moisture content and decreased growth performance, and feed additives evaluated were ineffective in ameliorating these negative effects. Finally, data collected from the feed efficiency survey suggest that there are knowledge gaps about practices that effect feed efficiency. Results from this survey will help extension educators better target specific industry segments with current information and provide more specific areas of future research where lack of information has been identified.

Dois experimentos foram conduzidos no Departamento de Zootecnia da ESALQUSP. No experimento 1, o objetivo foi avaliar o aumento do suprimento de proteína metabolizável (uréia x farelo de soja) para bovinos em crescimento, confinados com rações com teores altos de polpa cítrica. Foram utilizados 28 machos Nelore não castrados, com peso médio inicial de 293 kg e 14 meses de idade, agrupados em 14 baias. O delineamento experimental adotado foi o de blocos ao acaso. O período experimental teve duração de 93 dias, divididos em 3 sub-períodos de 31 dias. As rações com 16,5% de feno de Tifton e 83,5% de concentrado (%MS), foram isoprotéicas, formuladas utilizando o NRC (1996) Nível 1. Foram comparados 2 tratamentos. O tratamento U continha 2,3% de uréia na MS da ração e apresentava balanço positivo de PDR (proteína degradável no rúmen) e balanço negativo de PM (proteína metabolizável). O tratamento FS continha 6,61% de farelo de soja e 1,32% de uréia na MS da ração e apresentava balanços positivos de PDR e de PM. O ganho de peso diário (1,42 x 1,22 kg/cab) foi maior (P<0,05) para os animais do tratamento FS comparado com os do tratamento U. Houve tendência (P = 0,051) de maior consumo diário de MS (8,32 x 8,07 kg/cab) e tendência (P=0,058) de maior a eficiência alimentar (GPD/CMS) (0,172 x 0,153 kg) para os animais do tratamento FS em comparação com os do tratamento U. No experimento 2 o objetivo foi avaliar o aumento do suprimento de proteína metabolizável (uréia x farelo de soja) para bovinos em terminação, confinados com rações com teores altos de polpa cítrica. Foram utilizados 26 machos Canchim não castrados, com peso médio inicial de 351 kg e 14 meses de idade, agrupados em 14 baias. O delineamento experimental adotado foi o de blocos ao acaso incompletos. O período experimental teve duração de 93 dias, divididos em 3 sub-períodos de 31 dias. As rações com 16,5% de feno de Tifton e 83,5% de concentrado (%MS) foram isoprotéicas, formuladas utilizando o NRC (1996) nível 1. Foram comparados 2 tratamentos. O tratamento U continha 2,3% de uréia na MS da ração e apresentava balanços positivos de PDR (proteína degradável no rúmen) e de PM (proteína metabolizável). O tratamento FS continha 6,61% de farelo de soja e 1,32% de uréia na MS da ração e apresentava balanços praticamente nulo de PDR e positivo de PM. O consumo diário de MS (8,76 x 8,64 kg/cab), o ganho de peso diário (1,39 x 1,42 kg/cab) e a eficiência alimentar (GPD/CMS) (0,160 x 0,167 kg de GPD/kg MS) não diferiram (P>0,05) para os animais do tratamento FS em comparação com os animais do tratamento U respectivamente. Houve interação significativa (P<0,05) entre tratamentos e períodos para as variáveis ganho de peso diário e eficiência alimentar. No primeiro período experimental, os animais do tratamento FS ganharam mais peso (1,56 x 1,29 kg/cab) com maior eficiência (0,179 x 0,156) que os do tratamento U. No terceiro período experimental, os animais do tratamento U ganharam mais peso (1,31 x 1,00) com maior eficiência (0,143 x 0,110) que os do tratamento FS.
Two trials were conducted at the Animal Sciences Department, ESALQ/USP. Trial 1: The objective was to evaluate the increase in metabolizable protein supply (urea vs soybean meal) for feedlot growing bulls, fed diets high in citrus pulp. Twenty-eight Nellore bulls, averaging 293 kg of body weight and 14 months of age, were grouped in randomized blocks. Animals were housed in 14 pens (4x7m), and experimental period lasted 93 days, divided in three 31 days sub periods. Diets were isonitrogenous and contained 16.5% Tifton hay and 83.5% concentrate (%DM), formulated using NRC (1996) Level 1. Treatment U contained 2.3% urea in ration dry matter, with positive RDP (rumen degradable protein) balance and negative MP (metabolizable protein) balance. Treatment FS contained 6.61% soybean meal and 1.32% urea in ration dry matter, with positive RDP and MP balances. Average daily gain (1.42 x 1.22 kg) was highest (P<0.05) for animals in the FS treatment. There was a tendency (P = 0.051) for highest daily dry matter intake (8.32 x 8.07 kg) and a tendency (P= 0.058) for highest feed efficiency (ADG/DMI) (0.172 x 0.153) for animals in the FS treatment. Trial 2: The objective was to evaluate the increase in metabolizable protein supply (urea vs soybean meal) for feedlot finishing bulls, fed diets high in citrus pulp. Twenty-six finishing Canchim bulls, averaging 351 kg of body weight and 14 months of age, were grouped in randomized incomplete blocks. Animals were housed in 13 pens (4x7m), and experimental period lasted 93 days, divided in three 31 days sub periods. Diets were isonitrogenous and contained 16.5% Tifton hay and 83.5% concentrate (%DM), formulated using NRC (1996) Level 1. Treatment U contained 2.3% urea in ration dry matter, with positive RDP (rumen degradable protein) and MP (metabolizable protein) balances. Treatment FS contained 6.61% soybean meal and 1.32% urea in ration dry matter, with null RDP balance and positive MP balance. Daily dry matter intake (8.76 x 8.64 kg), average daily gain (1.39 x 1.42 kg) and feed efficiency (ADG/DMI) (0.160 x 0.167) were not different (P>0.05) for FS and U treatment respectively. There were significant interactions (P<0.05) between treatments and periods for average daily gain and for feed efficiency. In the first sub period, animals in treatment FS gained more weight (1.56 x 1.29 kg) with greater feed efficiency (0.179 x 0.156) than animals in treatment U. On the other hand, in the third sub period, animals in treatment U gained more weight (1.31 x 1.00 kg) with greater feed efficiency (0.143 x 0.110) than animals in treatment FS.

O Characifome dourado, Salminus brasiliensis, tem despertado crescente interesse dos piscicultores por apresentar rápido crescimento e ótima qualidade de carne. Porém, a falta de conhecimento sobre as exigências nutricionais e valor biológico dos alimentos para a espécie têm dificultado a formulação de dietas que permitam o máximo desempenho e, por conseqüência, sua produção intensiva. Para determinação da exigência nutricional em energia e proteína, juvenis de dourado (5,29 ± 0,21 g) foram distribuídos em 75 gaiolas (60 L) alojadas em tanques de 1.000 L e alimentados por 60 dias com dietas contendo níveis de proteína bruta (PB) entre 35 e 51% (incremento de 4%) e teores de energia bruta (EB) de 4.200 a 5.000 kcal/kg de alimento (incremento de 200 kcal/kg). O experimento foi conduzido em um delineamento inteiramente aleatorizado em esquema fatorial 5 × 5 (cinco níveis de EB e cinco níveis de PB, com três repetições). Foram avaliados parâmetros de ganho de peso (GP), ganho de peso relativo (GPR), consumo alimentar diário (CAD), índice de conversão alimentar (ICA), taxa de crescimento específico (TCE) e retenção de nutrientes. Não houve interação significativa (P>0,05) entre os níveis de proteína e energia para os parâmetros avaliados. Os valores de CAD, GP, GPR, CA e TCE e de retenção de nutrientes foram influenciados (P<0,05) pelos níveis de proteína e de energia da dieta. O CAD diminuiu com o aumento do nível energético das dietas. As relações lipo-somáticas e víscero-somáticas foram afetadas (P<0,05) pela energia dietética, aumentando com o aumento dos níveis de energia. Por meio do uso da regressão segmentada estimou-se a exigência protéica e energética para juvenis de dourado como sendo de 45,08% de PB e 4.600,0 kcal EB/kg, e uma relação energia:proteína variando entre 10,20 e 10,65 kcal de EB/g de PB, como ideal para ótimo desempenho e retenção de nutrientes e energia. Para avaliação do valor nutricional dos alimentos, foi determinado o coeficiente de digestibilidade aparente (CDA) da energia e nutrientes de fontes protéicas de origem animal e vegetal em dietas práticas para o dourado (19,49 ± 5,04 g). Os peixes, foram confinados em gaiolas de polipropileno (80 L; 40 peixes/gaiola) e alimentados com dietas teste granuladas que continham 30% do ingrediente teste e 70% de uma ração referência (RR) prática contendo 48,14% de PB, 4.453,2 kcal de EB/kg e 0,1% de óxido de crômio III. Após a última alimentação, as gaiolas eram transferidas para aquários cilindro-cônicos (200 L) onde as fezes eram coletadas por sedimentação em recipientes refrigerados. Houve diferença (P<0,01) para os CDAs dos nutrientes e energia das diferentes fontes protéicas. Foram obtidos valores de CDA de: 94,25; 91,26; 93,05 e 93,47% para a PB, 91,03; 90,33; 87,83 e 88,78% para a EB, 92,06; 84,49; 80,58 e 79,25% para matéria mineral, 83,90; 80,26; 84,25 e 84,55% para matéria seca e 97,38; 96,74; 93,32 e 91,46% para os lipídios, para a farinha de peixe (FP), farinha de vísceras (FV), farelo de soja (FS) e farelo de glúten de milho (FGM), respectivamente. O CDA médio dos aminoácidos foi de: 93,60; 89,95; 92,07 e 92,45% para FP, FV, FS e FGM, respectivamente. Todos os ingredientes testados foram eficientemente aproveitados e podem substituir parcialmente a FP em rações para o dourado.
The dourado, Salminus brasiliensis, presents excellent farming characteristics, such as fast growth and excellent flesh quality. However, the lack of the knowledge on the species nutritional requirements and biological value of feedstuffs hamper the formulation of diets for optimized performance and, consequently, the species\' intensive farming. To determine de species nutritional requirements, juveniles dourado (5.29 ± 0.21 g) were stocked in 75 cages (60-L) set up in 1,000-L containers, and fed for 60 days diets containing levels of crude protein (CP) between 35 to 51% (4% increments) and gross energy (GE) varying of 4,200 to 5,000 kcal/kg feed (200 kcal increments). The trial was set up in a completely randomized design, 5 × 5 factorial scheme (five levels of GE and five levels of CP, with three replications). Data on weight gain (WG), percentage weight gain (PWG), daily feed consumption (DFC), food conversion ratio (FCR), specific growth rate (SGR) and nutrient retention were recorded. No interaction (P>0.05) between dietary energy and protein levels for all parameters was detected. The values of DFC, WG, RWG, FCR, SGR and nutrient retention were affected (P<0.05) by the dietary protein and energy levels. DFC decreased with increasing energy levels. The liposomatic and viscerosomatic indexes were affected (P<0.05) by dietary energy levels, and increased with increasing energy levels. Through broken line analysis technique, the requirements estimated for optimum performance and nutrient and energy retention of dourado were 45.08% CP, 4,600.0 kcal GE/kg, and a energy:protein ratio varying between 10.20 and 10.65 kcal of GE/g of CP. Apparent digestibility is one of the main tools to evaluate the potential of an ingredient to be used in aquafeeds. To evaluate the apparent digestibility coefficient (ADC) of energy and nutrients of animal and plant protein sources in practical diets for the dourado (19.49 ± 5.04 g), fish were stocked in plastic cages (80-L) and fed pelleted test diets containing 30% of test ingredients plus 70% of a reference diet (RR) containing 48.14% CP, 4,453.2 kcal GE/kg, and 0.1% of chromium oxide III. After the last daily meal, cages were transferred to cylindrical conical-bottomed aquaria (200-L) where feces were collected by sedimentation in refrigerated containers. ADCs of nutrients and energy of selected protein sources differed (P<0.01); ADC values were: 94.25; 91.26; 93.05 and 93.47% for CP, 91.03; 90.33; 87.83 and 88.78% for GE, 92.06; 84.49; 80.58 and 79.25% for ash, 83.90; 80.26; 84.25 and 84.55% for dry matter, 97.38; 96.74; 93.32 and 91.46% for lipid for fish meal (FM), poultry by-product meal (PBM), soybean meal (SBM), and corn gluten meal (CGM), respectively. The average ADC of amino acids was: 93.60; 89.95; 92.07 and 92.45% of FM, PBM, SBM and CGM, respectively. All tested ingredients were efficiently used and can partially replace FM in diets for carnivorous dourado.

Existe uma série de evidências que os pintos de corte na fase pré-inicial têm seu sistema digestório ainda imaturo, implicando em menor capacidade de aproveitamento dos alimentos. Em função desse fato, ingredientes de maior digestibilidade seriam recomendados para proporcionar um desenvolvimento adequado do organismo. Com isso, o objetivo do presente trabalho foi determinar a energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) de ingredientes como fontes de carboidrato e proteína para frangos de corte na fase pré- inicial, bem como avaliar a utilização destes ingredientes sobre o desenvolvimento inicial de órgãos do trato gastrintestinal, desempenho e características da carcaça das aves. Os ingredientes avaliados foram: milho (MI), amido de milho (AMI), amido de mandioca (AMA), glicose (GLI), lactose (LAC) e sacarose (SAC), como fontes de carboidrato; e farelo de soja (FS), soja integral micronizada (SIM), isolado protéico de soja (IS), ovo em pó (OP), plasma sanguíneo (PS), farelo de glúten de milho (GM) e levedura seca (LS), como fontes de proteína. Para a determinação da EMAn foram desenvolvidos vários ensaios de metabolismo utilizando-se o método de coleta total de excretas. Para a avaliação do desempenho, desenvolvimento do trato gastrintestinal e características da carcaça foram conduzidos diversos experimentos, em gaiolas e em piso de galpão experimental, com a inclusão dos ingredientes nas dietas. Os valores de EMAn para a fase pré- inicial das fontes de carboidrato foram: 3.213; 3.269; 3.690; 3.427; 1.225 e 3.524 kcal/kg para MI, AMI, AMA, GLI, LAC e SAC, respectivamente. Para as fontes protéicas a EMAn foi: 2.085; 4.068; 2.110; 5.095; 3.831; 3.374 e 2.037 kcal/kg para FS, SIM, IS, OP, PS, GM e LS, respectivamente. Para as aves criadas em gaiolas pode-se dizer que o desenvolvimento do trato gastrintestinal, de maneira geral, não foi influenciado pelas diferentes fontes de carboidrato, mas o consumo de ração das aves foi aumentado pelo fornecimento de carboidrato de maior disponibilidade na dieta préinicial, contribuindo para um aumento no peso vivo das aves. As diferentes fontes de proteína afetaram o desenvolvimento dos órgãos, mas esse efeito não foi suficiente para explicar as variações no desempenho das aves. A adição de diferentes fontes de proteína e carboidrato, bem como suas misturas, em dietas pré- iniciais de frangos de corte criados sob piso de galpão experimental, promoveram alterações no desempenho e no desenvolvimento do intestino delgado das aves até o sétimo dia de idade, entretanto as diferenças de desempenho não foram mantidas nas fases subseqüentes, contribuindo para que as características da carcaça e composição da carne de perna não apresentassem diferenças no momento do abate.
There are some evidences in the literature that newly hatched chicks have the digestive system still immature, what result in a small capacity to metabolize feed ingredients. So, more digestible ingredients could be recommended to allow an adequate development of the body. Herewith, the objective of this work was to determine the Ncorrected apparent metabolizable energy (EMAn) of carbohydrate and protein sources for newly hatched chicks, and to evaluate the utilization of these ingredients on the early development of gastrointestinal tract organs, performance and carcass characteristics of birds. The ingredients evaluated were: corn (MI), corn starch (AMI), cassava starch (AMA), glucose (GLI), lactose (LAC) and sucrose (SAC), as carbohydrates sources, and soybean meal (FS), micronized full fat soybean (SIM), isolated soy protein (IS), dried whole eggs (OP), blood plasma (PS), corn gluten meal (GM) and dried sugar cane yeast (LS), as protein sources. Several metabolism trials were conducted to determine the EMAn, using the total excreta collection method. To evaluate the performance, gastrointestinal tract development and carcass characteristics, experiments were conducted, in cages and floor pens, using diets containing those ingredients. The EMAn of the carbohydrate sources determined for chicks in the first week were: 3,213; 3,269; 3,690; 3,427; 1,225 and 3,524 kcal/kg for MI, AMI, AMA, GLI, LAC and SAC, respectively. The EMAn for protein sources were: 2,085; 4,068; 2,110; 5,095; 3,831; 3,374 and 2,037 kcal/kg for FS, SIM, IS, OP, PS, GM and LS, respectively. For the birds reared in cages, the results showed, in general, that the different carbohydrate sources did not affect the gastrointestinal tract development, but the feed consumption of the birds was improved by the more available carbohydrate sources in the newly hatched chicks diets, contributing to a higher liveweight of the birds. Otherwise, the different protein sources affected the gastrointestinal tract development, but these effects did not explain the changes on broiler performance. The addition of different protein and carbohydrate sources, and their mixtures, in the diets of newly hatched chicks reared in the floor pens resulted in differences on performance and on small intestine development of the birds until seven days of age, but these differences were not maintained on the following phases, contributing to a similar carcass characteristics and similar chemical composition of the whole leg meat at slaughter time.

The role of ammonia in reproductive inefficiency in early lactation dairy cows was studied in a series of experiments designed to determine the concentrations of ammonia in normal bovine follicular fluid (bFF), to determine the effects of ammonia on the bovine embryo during specific stages of development, and to test the hypothesis that elevated plasma urea nitrogen concentration is associated with elevated ammonia and urea nitrogen concentrations in the reproductive fluids. In the first study, ammonia concentration in different size follicles and the effect of ammonia during in vitro maturation on embryo development were determined. Ammonia concentration in the bFF was significantly different (P<0.001) between each follicle size (< 1 mm, 2-4 mm, 5-8 mm, and >10 mm) and ammonia concentration decreased as follicle size increased. There was no difference (P>0.05) in cleavage rates, morula development, and blastocyst development when oocytes were exposed to various concentrations of ammonia during in vitro maturation. In the second study, the effects of addition of ammonia in the media during in vitro fertilization (IVF), culture (IVC), and throughout maturation (IVM), IVF, and IVC were evaluated. Addition of moderate concentrations of ammonia to IVF media resulted in a significant (P<0.05) increase in embryos that developed to blastocysts and to expanding and hatching blastocysts. Ammonia in the IVC media significantly (P<0.05) decreased the proportion of ova that developed to blastocysts. When exposed to ammonia throughout IVM, IVF, and IVC, ova developing to morulae was significantly (P<0.05) higher in media containing moderate concentrations of ammonia compared to control. In the third study, plasma urea nitrogen (PUN) concentrations were related to follicular and uterine fluid ammonia and urea concentrations in early lactation dairy cows. Mean PUN concentrations were used to distribute the cows into two groups: 1) cows with PUN ≥ 20 mg/dl (HPUN), and 2) cows with PUN<20mg/dl (LPUN). Follicular fluid ammonia and follicular fluid urea were significantly (P<0.01) higher in HPUN cows compared to LPUN cows. Uterine fluid ammonia concentration was significantly (P=0.05) higher in HPUN cows than in LPUN cows during the luteal phase, but not during the estrus phase of the estrous cycle, but not on Day 0. Uterine fluid urea nitrogen concentrations were significantly (p<0.001) higher in HPUN cows than in LPUN cows during both the luteal and estrus phases.

Excessive dietary protein may affect MP use because of energetic costs of excreting excess N. Amino acids also may influence post-ruminal digestion. Therefore, two experiments were designed to evaluate the effects of MP intake and post-ruminal flow of AA on growth performance and pancreatic digestive enzymes. In experiment 1, treatments supplied different amounts of MP intake to cattle and the effects on growth performance and feeding behavior were evaluated. In experiment 2, duodenal infusion of glutamate or casein was examined and the effects on pancreatic enzymes were measured. Experiment 1 suggests that feeding steers 906 g MP/d in finishing diets supplied enough MP for the greatest growth performance and carcass characteristics. Interestingly, MP intake caused different responses on feeding behavior with greater effects on steers fed 626 and 1444 g MP/d. In experiment 2, casein infusion increased α-amylase activity but not trypsin activity. Glutamate did not influence pancreatic digestive enzymes.

Conselho Nacional de Desenvolvimento Científico e Tecnológico
Die to rapid growth of aquaculture and the consequent increase for aquaculture feed, the industry's main challenge is to identify potential dietary ingredients that ensure satisfactory performance, economic viability and quality of fish. Considering this demand, the aim of this study was to evaluate the combination of different protein sources on feeding of jundiá juvenile, and their effects on growth, metabolism and quality of fish. Three experiments were conducted. In experiment 1, diets containing alternative protein sources in combination with soybean meal were evaluated: PMM: porcine meat meal; CM: canola meal; SFM: sunflower meal; PBM: poultry by-product meal. After 12 experimental weeks, jundiá fed diets PMM and PBM showed greater weight gain and better feed conversion than those fed diets with plant-protein diets. The enzyme activity, intestinal quotient and somatic indices changed according to the dietary protein source. Fish fed diets PMM and PBM had higher concentrations of plasma triglycerides and cholesterol, and higher fat content in fillet and whole fish, reflecting the higher fat diets. Fish fed diets CM and SFM had lower protein deposition. In the second experiment, the aim was to evaluate the effect of supplementation strategies for limiting amino acids in the diet of jundiá on growth, metabolic response and possible impact on fillet quality. The experimental diets were: CON: porcine meat meal + soybean meal, supplemented with lysine and methionine; MIX: mixture of plant and animal-protein sources, without supplementation of synthetic amino acids; VEG: mixture of plant-protein meals and supplementation with lysine and methionine. At the end of eight weeks trial, there were no significant differences on the performance and fillet composition. However, there were changes in metabolic response of jundiá die to diet composition, which was reflected in body fat content. The VEG diet altered the color and brightness of fillets, although these differences were not detected in the sensory analysis. The third experiment was conducted to evaluate the apparent digestibility coefficients (ADC) of dry matter, organic matter, crude protein, gross energy and fat of the following ingredients: canola meal, porcine meat meal, sunflower meal, soybean meal and poultry by-product meal. Feces were collected in modified Guelph system, using chromium oxide (0.2% in diet) as marker. From the ADC of diets were estimated ADC of ingredients. Porcine meat meal showed the worst digestibility coefficients for all nutritional fractions (about 30%), whereas plant-protein sources showed good digestibility coefficients (between 70 and 80%). Based on the results obtained in this work, we can conclude that: canola meal or sunflower meal in combination with soybean meal in large quantities are not an alternative dietary protein to jundiá; The combination of three plant protein meals, included in small amounts in the diet can provide similar weight gain to that obtained with the CON diet; There is no need for supplementation of free amino acids in diets composed by the combination of vegetable and animal meals in small proportions.
Com o crescimento acelerado da aquicultura e consequente aumento da demanda por rações aquícolas, o principal desafio da indústria consiste em identificar ingredientes potenciais para inclusão nas dietas, que garantam desempenho satisfatório, viabilidade econômica e qualidade do pescado. Considerando esta demanda, o objetivo deste trabalho foi avaliar a combinação de fontes proteicas de origem animal e vegetal na alimentação de juvenis de jundiá, e seus efeitos sobre o crescimento, metabolismo e a qualidade do pescado. Foram conduzidos três experimentos, dois de crescimento e um de digestibilidade. No experimento 1, foram avaliadas dietas contendo fontes proteicas alternativas em combinação com farelo de soja: FCS: farinha de carne suína; FCN: farelo de canola; FGI: farelo de girassol; FVA: farinha de vísceras de aves. Ao final de 12 semanas, os jundiás alimentados com as dietas FCS e FVA apresentaram maior ganho em peso e melhor conversão alimentar que os alimentados com as dietas vegetais. A atividade enzimática, o quociente intestinal e os índices hepato e digestivo-somático foram alterados em função da fonte proteica da dieta. Os peixes alimentados com as dietas FCS e FVA apresentaram maior concentração de triglicerídeos e colesterol plasmáticos, além de maior percentual de gordura no filé e no peixe inteiro, como reflexo do maior teor de gordura nas dietas. Os peixes alimentados com as dietas FCN e FGI apresentaram menor taxa de deposição de proteína corporal e no filé. No segundo experimento, o objetivo foi avaliar o efeito de estratégias de suplementação de aminoácidos limitantes na dieta de jundiás sobre o desempenho zootécnico, resposta metabólica e possíveis reflexos na qualidade dos filés. As dietas avaliadas foram: CON: farinha de carne suína+farelo de soja+suplementação com lisina e metionina; MIX: mistura de farelos vegetais e farinhas animais sem suplementação de aminoácidos livres; VEG: mistura de farelos vegetais e suplementação com lisina e metionina. Ao final de oito semanas, não foram observadas diferenças significativas no desempenho zootécnico e composição dos filés nos diferentes tratamentos. Entretanto, houve alteração da resposta metabólica dos jundiás em função da composição da dieta, que se refletiu no teor de gordura corporal. A dieta VEG alterou a cor e a luminosidade dos filés de jundiá. Entretanto, estas diferenças não foram detectadas na análise sensorial. O terceiro experimento foi realizado para avaliar os coeficientes de digestibilidade aparente (CDA) da matéria seca, matéria orgânica, proteína bruta, energia bruta e gordura dos seguintes ingredientes: farelo de canola, farinha de carne suína, farelo de girassol, farelo de soja e farinha de aves. As fezes foram coletadas em sistema de Guelph modificado, utilizando óxido de cromo (0,2% na dieta). A partir dos CDA das dietas foram estimados os CDA dos ingredientes. A farinha de carne suína apresentou os piores coeficientes de digestibilidade para todas as frações nutricionais (em torno de 30%), enquanto que as fontes proteicas vegetais apresentaram bons coeficientes de digestibilidade (entre 70 e 80%). Com base nos resultados obtidos, pode-se concluir que: Os farelos de canola ou de girassol em combinação com o farelo de soja, em grandes quantidades, não se apresentam como alternativa proteica na dieta de jundiás na fase de recria/engorda; A combinação de farelos vegetais, incluídos em pequenas quantidades na dieta, é capaz de proporcionar ganho em peso semelhante ao obtido com a dieta controle; Não há necessidade de suplementação de aminoácidos livres em dietas compostas pela combinação de farelos vegetais e farinhas animais em pequenas proporções.

Master of Science
Department of Animal Sciences and Industry
Michael D. Tokach
A total of 5,212 nursery pigs were used in 11 experiments to evaluate amino acids in nursery pig diets. Experiments 1 and 2 were conducted to determine whether the Lys level fed during one phase of the nursery influenced the response to Lys during subsequent phases. Experiment 1 tested a wide range of dietary Lys in 2 phases and reported that pigs fed high Lys during each period had increased growth performance; however, compensatory growth occurred for the pigs previously fed low Lys diets, resulting in no impact on overall ADG or final BW. Experiment 2 tested a narrow range of dietary Lys in 3 phases and found that marginally deficient diets can be fed in the early nursery phases without influencing final BW or the response to Lys levels in subsequent phases. Both experiments demonstrate that the low dietary Lys levels used in each can be fed in the early nursery phases with no negative impact on overall nursery growth rate provided that adequate levels are fed thereafter. Experiments 3 to 6 were conducted to determine the standardized ileal digestible (SID) Lys requirement of nursery pigs from 7- to 14-kg. Data from all experiments were combined and break-point and quadratic broken-line analysis was used to determine the estimated SID Lys requirement. The SID Lys requirement for optimal growth was at least 1.30% for ADG and 1.37% for G:F, or at least 3.86 and 4.19 g SID Lys/Mcal ME, respectively. Experiments 7 to 11 were conducted to evaluate the effect of replacing specialty protein sources with crystalline AA and AA requirements for 7- to 12-kg pigs. Experiment 7 demonstrated that crystalline AA can be used to replace fish meal in diets with no negative effects on growth performance. Experiment 8 demonstrated that L-Trp, L-Val, and a source of non-essential AA were needed in low-CP, AA-fortified nursery diets to achieve maximum growth performance, whereas the addition of L-Ile was not required. Experiment 9 indicated that feeding greater than 7.35% total Lys:CP decreased growth performance and Exp. 10 indicated that a SID Val:Lys ratio of 65% was sufficient for optimal growth of early nursery pigs. Implementing the results from the previous experiments, Exp. 11 determined that crystalline AA in nursery pigs diets can replace high amounts of fish meal, meat and bone meal, and poultry meal when balanced for minimum AA ratios and maximum Lys:CP with no negative effect on growth performance.

O estudo consistiu de dois experimentos com o objetivo de avaliar o efeito metabólico, custos e viabilidade econômica de dietas com diferentes fontes nitrogenadas e teores proteicos. No primeiro experimento avaliou-se o efeito de dois teores de proteína bruta (PB) (130 e 148g/kg de MS) e duas fontes nitrogenadas (farelo de algodão 38 e grão de soja cru integral) na dieta de vacas leiteiras com cana de açúcar como volumoso, sobre as frações nitrogenadas do leite, balanço de nitrogênio e perfil metabólico. Foram utilizadas 12 vacas da raça Holandesa com 155 (±65) dias em lactação, agrupadas em três quadrados latinos 4x4 contemporâneos, com período experimental de 21 dias, sendo 14 dias para adaptação às dietas e os sete últimos para a realização das coletas. As vacas foram alojadas em baias individuais e alimentadas ad libitum. As amostras de leite para análise do balanço nitrogenado e frações nitrogenadas foram coletadas no 15° dia de cada período. O consumo e balanço de nitrogênio foram maiores para vacas alimentadas com dietas com 148 g PB/kg de MS. Por outro lado, vacas alimentadas com dietas contendo farelo de algodão apresentaram maior excreção de nitrogênio no leite do que vacas alimentadas com grão de soja cru integral. A relação entre caseína e proteína verdadeira no leite foi maior em vacas alimentadas com grão de soja cru integral. Houve interação entre fonte nitrogenada e teor de PB da dieta sobre as concentrações de nitrogênio ureico no leite (NUL) e nitrogênio não proteico (NNP). A concentração de NUL foi maior em vacas alimentadas com farelo de algodão e com maior teor de PB, em contrapartida houve menor excreção de NUL em vacas alimentadas com grão de soja com maior teor proteico. Não houve efeito das dietas sobre os teores de proteína do leite, nitrogênio não caseinoso (NNC), caseína e proteína do soro. Conclui-se que o uso de dietas com 130g de PB/Kg na MS não altera o balanço de nitrogênio e de composição do leite de vacas leiteiras em comparação com teores de 148g/Kg de PB na MS, e resultam em menor excreção de nitrogênio no ambiente. No segundo experimento foram calculados os custos e margens totais de dietas com cinco fontes nitrogenadas principais (ureia, farelo de soja, farelo de algodão, grão de soja cru integral e farelo de glúten de milho) e cinco teores proteicos (130, 145, 148, 157 e 160 g/kg de MS) com cana de açúcar como volumoso para vacas em lactação. Os dados foram provenientes de três estudos conduzidos com a finalidade de coleta de dados produtivos e respostas metabólicas. A análise econômica foi realizada com base nos preços históricos deflacionados (corrigidos do efeito da inflação) praticados durante o período 2002 a 2012, e no cálculo dos custos de alimentação, em função do consumo de alimento, da produção de leite e do teor de proteína bruta no leite. Dietas com cana de açúcar com teor proteico de 14,5% com ureia como fonte nitrogenada principal apresentaram a maior margem bruta (diferença entre a receita da venda do leite e do custo da dieta) com valor médio anual de R$1,85.vaca-1.dia-1. A dieta com 14,8% de PB com grão de soja cru integral apresentou a menor margem bruta de R$ 2,16.vaca-1.dia-1.
The study consisted of two experiments to evaluate the N balance and economical analysis of diets with different nitrogen sources and crude protein levels. On the first experiment it was evaluated the effect of two crude protein (CP) levels (130 e 148 g/kg DM) and two nitrogen sources (cottonseed meal 38% and whole raw soybean) in diets of dairy cows using sugar cane as forage on nitrogen in milk, nitrogen balance and metabolic parameters. Twelve Holstein cows with 155 (±65) days in lactation were distributed into three contemporary 4x4 Latin squares, with experimental period of 21 days, 14 days for diet adaptation and the remaining seven days for sampling. The cows were housed in individual pens and fed ad libitum. Milk samples for nitrogen balance and milk nitrogen fractions analysis were collected on the 15th day of each experimental period. Nitrogen intake and nitrogen balance were higher for the cows fed diets with 148 g CP/kg DM. However cows fed diets with cottonseed meal had higher nitrogen excretion in milk than cows fed diets with whole raw soybean. The casein: true milk protein ratio was higher in cows fed diets with whole raw soybean. There was interaction between the nitrogen source and the diet CP content on the milk urea nitrogen and non-protein nitrogen. Milk urea nitrogen was higher in cows fed diets with cottonseed meal and higher CP concentrations, however lower milk urea nitrogen was observed in cows fed diets with whole raw soybean and higher CP concentration. The concentration of crude protein, noncasein protein, casein and whey protein in milk did not differ between diets. In conclusion the use of low concentrations of protein (130g/Kg in MS) does not affect the performance of dairy cows and provides lower excretion of nitrogen in the environment. On the second experiment, the costs and the gross margin were calculated for diets formulated with five nitrogen sources (urea, soybean meal, cottonseed meal, whole raw soybean and corn gluten meal) and five protein levels (130, 145, 148, 157 e 160 g/kg DM) using sugar cane as forage. Performance data were obtained from three experiments conducted previously. Economical analysis were performed based on historical prices adjusted for the effect of inflation during the period between 2002 and 2012 and based on the feed costs, cow intake, milk prodution and milk protein levels. The higher gross margin (difference between the income from milk sale and diet costs) were obtained for 145 g/kg of CP in DM diets and urea as main nitrogen source, with mean of R$1,85.vaca-1.dia-1. The lower gross margin were observed in the 148 g/kg of CP in DM diet and whole raw soybean as nitrogen source, with mean of R$ 2,16.vaca-1.dia-1.

A produção comercial de peixes carnívoros exige o uso de um conjunto complexo de práticas de manejo da produção e alimentação, à redução do impacto ambiental dos alimentos e à minimização do emprego de fontes protéicas de origem animal nas formulações das dietas. O objetivo do presente estudo foi investigar o uso de atrativos alimentares em dietas formuladas exclusivamente à base de proteína de origem vegetal (PV), e seus efeitos no desempenho, composição corporal e digestibilidade das dietas pelo carnívoro “black bass”, Micropterus salmoides, condicionados a aceitar ração seca. Novecentos juvenis (26,54 ± 1,53 g) foram estocados em 60 aquários de polietileno de 90 L (15 peixes/aquário), em delineamento experimental totalmente ao acaso (n=3), e alimentados ad libitum em duas refeições diárias (07h00m e 17h00m), durante 13 dias, com uma dieta basal (100% PV) contendo seis níveis de proteína solúvel de peixe – PSP (0,5, 1,0, 1,5, 2,0, 2,5 e 3,0%); Fisharom ® – FA (0,02, 0,04, 0,06, 0,08, 0,10 e 0,12%); silagem de peixe – SP (1,0, 2,0, 3,0, 4,0, 5,0 e 6,0%); um controle positivo (10% de farinha de peixe) e um controle negativo (dieta basal sem atrativos). Os peixes alimentados com a dieta contendo FA 0,02% apresentaram melhor taxa de crescimento, ganho de peso e conversão alimentar, mas não apresentaram diferenças dos demais tratamentos (P>0,05). Os peixes alimentados com dietas contendo SP como atrativo apresentaram os piores resultados de desempenho. Em uma segunda etapa, foi avaliado o desempenho e a composição corporal de 560 juvenis (3,06 ± 0,20 g) estocados em gaiolas de 60 L, dentro de caixas de polietileno de 1.000 L, instaladas em laboratório com um sistema fechado de recirculação de água com temperatura (27 o C ± 1,07 o C) e fotoperíodo (14L:10E) controlados, em um delineamento experimental totalmente ao acaso (n=4), e alimentados ad libitum em duas refeições diárias (07h00m e 17h00m), durante 43 dias, com 7 dietas isonitrogenadas (40% de PB) e isocalóricas (3.500 kcal/kg), contendo níveis decrescentes de proteína de origem vegetal: 100PV:00PA; 100PV + 0,02% Fisharon ® ; 80PV:20PA; 60PV:40PA; 40PV:60PA; 50PV:50PA (sem farinha de peixe); e uma dieta controle (ração comercial). A inclusão de farinha de peixe e farinha de penas foi limitada em 7%; a inclusão de farinha de vísceras e farinha de carne em 15%. DL-metionina (98%) e L-lisina (80%) foram adicionadas automaticamente através de matriz de aplicativo de formulação de ração. Em uma terceira etapa, foi avaliada a digestibilidade das rações utilizadas no experimento anterior. Para tanto, 1.960 juvenis (14,0 ± 1,0 cm) foram confinados em gaiolas de polipropileno e alimentados durante 40 dias, no período diurno, com as sete dietas do experimento anterior acrescidas de 0,5% de óxido de cromio. No período noturno as gaiolas eram transferidas para aquários cilíndrico-cônicos de 200 L, onde as fezes eram coletadas por sedimentação em recipiente refrigerado. O farelo de soja pode ser utilizado como substituto parcial de fontes protéicas e origem animal em rações formuladas para o “black bass”; a farinha de vísceras pode ser considerada uma boa opção como fonte protéica de origem animal em rações. Os melhores resultados de desempenho foram relacionados aos tratamentos controle e 50PV:50PA. A necessidade do uso da farinha de peixe na formulação de dietas para espécies carnívoras é no mínimo questionável e a determinação da digestibilidade das rações, visando maior precisão em formulações de custo mínimo para peixes carnívoros, deve ser prática corrente na indústria da alimentação de peixes.
Commercial farming of carnivorous fish demands the use of a complex group of practices of production and feeding management, the reduction of the environmental impact of the feeds and the minimization of the use of animal protein sources in the diets. The present study investigated the use of feed stimulants in diets formulated exclusively out of plant protein, and their effects in growth performance, body composition and digestibility of the feeds for the carnivore largemouth bass, Micropterus salmoides, conditioned to accept dry feed. Nine hundred juvenile largemouth bass (26.54 ± 1.53 g) were stocked in 60, 90-L polyethylene aquaria (15 fish/aquarium), in a totally randomized experimental design (n=3). Fish were fed ad libitum two daily meals (0700 and 1700), for 13 days, with a basal diet (100% plant protein) containing increasing levels of fish soluble protein – FSP (0.5, 1.0, 1.5, 2.0, 2.5, and 3.0%); Fisharom TM – FA (0.02, 0.04, 0.06, 0.08, 0.10 and 0.12%); fish silage – FS (1.0, 2.0, 3.0, 4.0, 5.0 and 6.0%); a positive control (10% of fish meal) and a negative control (basal diet without stimulants). Fish fed the diet containing 0.02%FA presented better growth rate, weight gain and feed conversion rate, but did not differ from the other treatments (P>0,05). Fish fed diets containing FS as stimulant presented the poorest performance. Next, the effect of different levels of dietary plant protein in the performance and body composition of the species was evaluated. Five hundred and sixty juvenile largemouth bass (3.06 ± 0.20 g) were stocked in 60-L cages, inside 1,000-L polyethylene tanks, installed at a laboratory with closed water-recirculating system and controled temperature (27 o C ± 1.07 o C) and photoperiod (14L:10D). Fish were fed ad libitum two daily meals (0700 and 1700), for 43 days, with 7 isonitrogenous (40% of PB) and isoenergetic (3,500 kcal/kg) diets, containing decreasing levels of plant protein: 100PP:00AP; 100PP + 0.02% Fisharom®; 80PP:20AP; 60PP:40AP; 40PP:60AP; 50PP:50AP (without fish meal); and a control diet (commercial feed). Inclusion of fish meal and feathers meal was limited to 7%; the inclusion of poultry by-product meal and meat and bone meal to 15%. DL methionine (98%) and L-lysine (80%) were added automatically through feed formulation software matrix. Trial was set up in a totally randomized experimental design (n=4). Finally, digestibility of the diets used in the experiment 2 was studied. One thousand, nine hundred and eighty juvenile largemouth bass (14.0 ± 1.0 cm) conditioned to accept artificial, dry feed were confined in polypropilene cages and fed, for 40 days, in day time, with the seven experimental diets added of 0.5% of cromic oxide. In the night, cages were transferred to cylindrical-conical bottomed, 200-L aquaria, where feces were collected by sedimentation into refrigerated containers. Data were submitted to the ANOVA and Tukey’s test of comparison of means through statistical software package SAS (P=0.05). Soybean meal can be used as partial substitute of animal protein in diets for largemouth bass; the poultry by-product meal shows as a good option as animal protein source in these rations. Best performances were related to the control treatments and 50PP:50AP; the need for the use of fishmeal in the formulation of diets for carnivorous species is, at least, questionable. Results of the digestibility trials demonstrated the importance of determining the digestibility of the rations, if precision in the formulation of least-cost feeds for carnivorous fish is the ultimate goal.

A produção da farinha de penas hidrolisadas (FPH) está atrelada a produção de carne de frango. O processo da FPH é a hidrólise térmica, o que pode reduzir a disponibilidade de aminoácidos (aa) essências devido à alta temperatura e pressão que as penas são submetidas. O uso de micro-organismos (MIC) para hidrólise pode ser uma alternativa vantajosa por minimizar essas perdas. Foram conduzidos três experimentos com o objetivo de avaliar a capacidade de degradação das penas por MIC, o coeficiente de digestibilidade aparente (CDA) das classes nutricionais e energia. Também avaliar as características fecais e urinárias em cães alimentados com dietas contendo FPH por micro-organismo Bacillus subtilis (FPHm) ou maneira convencional (FPHc) e a palatabilidade da FPHm. No experimento 1, foram realizadas hidrólises in vitro de penas, utilizando quatro cepas de MIC diferentes e blend enzimático, foram determinados o fator de degradação, o teor de proteína solúvel, a digestibilidade in vitro e aa livres. No experimento 2, determinou-se CDA das dietas experimentais com inclusão por cobertura de 10% de FPHm ou FPHc sobre a dieta basal e a influência nas características fecais e urinárias, além da observação da resistência dos Bacillus subtilis ao passar pelo trato gastrointestinal (TGI) No terceiro experimento, foi realizado teste de palatabilidade, utilizando o método “two-pan” com as mesmas dietas testadas no experimento 2. Os resultados do experimento 1 indicaram que os MIC utilizados tiveram capacidade de degradar as penas e de melhorar a solubilidade proteica quando as penas foram adicionadas em concentrações de 5 e 8%. No experimento 2, os CDA da matéria seca (MS), PB e energia foram menores para a dieta contendo 10% de FPHm (P < 0,05). Apesar de não haver diferença entre os tratamentos para densidade urinária, pH urinário e fecal e escore fecal (P > 0,05), os animais que consumiram dietas com FPHm produziram maior quantidade de fezes (MS) diárias (P < 0,05). Os valores de energia digestível para FPHm e FPHc foram 2.198 e 4.443 kcal/kg, respectivamente. Foi possível verificar maior presença de Bacillus sp. nas fezes dos cães que receberam FPHm, demonstrando que os MIC sobreviveram ao TGI. No experimento 3, a inclusão da FPHm melhorou significativamente a palatabilidade nas dietas para cães adultos (P < 0,05).
The production of hydrolyzed feather meal (FPH) is linked to the production of chicken meat. The process of FPH is thermal hydrolysis, which may reduce the availability of amino acids (aa) essences due to the high temperature and pressure that the feathers are subjected to. The use of microorganisms (MIC) for hydrolysis may be an advantageous alternative to minimize such losses. Three experiments were carried out with the objective of evaluating feather degradability by MIC, the apparent digestibility coefficient (CDA) of the nutritional and energy classes, and to evaluate fecal and urinary traits in dogs fed diets containing FPH by microorganism Bacillus subtilis (FPHm) or conventional manner (FPHc) and the palatability of FPHm. In experiment 1, in vitro hydrolyses of feathers were performed, using four different MIC strains and enzymatic blend, and the degradation factor, soluble protein content, in vitro and free digestibility were determined. In Experiment 2, CDA was determined from the experimental diets with inclusion of 10% FPHm or FPHc on the basal diet and the influence on fecal and urinary traits, as well as the observation of Bacillus subtilis resistance when passing through the gastrointestinal tract (TGI) In the third experiment, a palatability test was performed using the two-pan method with the same diets tested in experiment 2. The results of experiment 1 indicated that the MICs used had the ability to degrade feathers and to improve protein solubility when the feathers were added in concentrations of 5 and 8%. In experiment 2, CDA of dry matter (DM), CP and energy were lower for the diet containing 10% FPHm (P <0.05). Although there was no difference between the treatments for urinary density, urinary and fecal pH and fecal score (P> 0.05), the animals that consumed diets with FPHm produced a greater amount of feces (P <0.05). The digestible energy values for FPHm and FPHc were 2,198 and 4,443 kcal / kg, respectively. It was possible to verify greater presence of Bacillus sp. in the faeces of the dogs that received FPHm, demonstrating that the MICs survived the TGI. In experiment 3, the inclusion of FPHm significantly improved palatability in diets for adult dogs (P <0.05)

Master of Science
Department of Animal Sciences and Industry
Joel DeRouchey
Mike Tokach
Six experiments using 3,862 pigs were conducted to evaluate effects of ractopamine HCl (RAC) feeding programs, dietary L-Carnitine and dried distillers grains with solubles (DDGS) on growth, carcass traits, loin and jowl fat quality of pigs, and energy and protein sources in nursery diets. In Exp. 1 and 2, RAC-fed pigs had greater (P<0.05) ADG, G:F and HCW compared with the control. Within RAC treatments, there were no differences in growth. Pigs fed step-up RAC had increased (P<0.01) percentage lean, fat-free lean index and loin depth but decreased (P<0.01) backfat than the control or constant treatment. In Exp. 2, pigs fed step-up RAC program had greater (P<0.05) ADG and G:F than the constant treatment. Pigs fed constant RAC had greater (P=0.002) carcass yield than controls. There were no overall differences in other carcass traits among treatments. In Exp. 3, dietary L-Carnitine improved (P<0.02) ADG and final BW. A DDGS × L-Carnitine interaction (quadratic, P<0.01) was observed for G:F. Pigs not fed DDGS had similar G:F, but in DDGS diets pigs fed 50 ppm L-Carnitine had worse G:F than those fed 100 ppm. Pigs fed L-Carnitine had greater (P<0.02) HCW compared with those not fed L-Carnitine. Increasing L-Carnitine up to 100 ppm increased HCW (quadratic, P<0.03) and backfat (quadratic, P<0.04), with the maximum response at 50 ppm dietary L-Carnitine. Increasing L-Carnitine increased (linear, P<0.04) purge loss of loin. Feeding DDGS increased (P<0.001) linoleic acid and iodine value of jowl fat compared with feeding no DDGS. However, feeding L-Carnitine did not change jowl fatty acid composition. In Exp. 4, 5 and 6, nursery pigs fed choice white grease (CWG) had improved (P<0.02) G:F than pigs fed a control diet or an alcohol based energy source. Also, pigs fed CWG had greater (P<0.04) ADG in Exp. 4 and 6 and had reduced (P<0.01) ADFI in Exp. 5. The alcohol based energy source improved (P<0.04) ADG and ADFI with no change in G:F in Exp. 4; but did not affect growth in Exp. 5 and 6. In Exp. 6, pigs fed AV-E Digest had equal performance as nursery pigs fed other specialty proteins.

Aunque el uso de altos niveles de fuentes de proteína vegetal en piensos para doradas de engorde se ha alcanzado con éxito en cuanto al crecimiento, estas dietas todavía están asociadas a efectos negativos en la eficiencia nutricional y en la capacidad inmunitaria. El intestino es el órgano donde se produce la primera interacción entre el pez, los nutrientes y las bacterias del medio, y desarrolla un papel crucial en la digestión de los nutrientes y la respuesta infamatoria e inmune. Esta tesis doctoral se centra en el impacto de distintas dietas con altos niveles de proteína vegetal, y especialmente, en la evaluación del estatus intestinal de las doradas de engorde alimentadas con altos niveles de sustitución de la harina de pescado durante un periodo largo de tiempo. Los cambios observados en el intestino se caracterizaron mediante el uso de distintas estrategias, como el análisis de la digestibilidad y la retención de amino ácidos, de la excreción de amonio, de la actividad de enzimas digestivos, de los cambios histológico o de la expresión de genes relacionados con la función y el mantenimiento de la arquitectura intestinal, así como técnicas ómicas para el análisis del proteoma y de la microbiota intestinal. Se ensayaron distintos niveles de sustitución de harina de pescado, pero el impacto de las dietas con una sustitución completa, bien complementada con subproductos de origen marino o suplementada con aminoácidos libres sintéticos, recibió mayor atención. La sustitución completa de la harina de pescado provocó una reducción, aunque ligera, del crecimiento y de la eficiencia digestiva y nutritiva de la dorada de engorde, aunque el impacto sobre el crecimiento era mayor cuando los peces eran alimentados desde la época de juveniles con estas dietas. La digestibilidad y el nivel de síntesis de proteína se vio alterada, aunque no se observaron diferencias significativas en la actividad enzimática digestiva. No obstante, el impacto de las fuentes vegetales cuando no había fuentes de proteína marina en la dieta era especialmente crítico para la supervivencia de los peces. En el intestino de estos peces solo se observaron diferencias menores relacionadas con la inflamación a nivel histológico, pero también se observó una disminución en la expresión génica de genes involucrados en la inflamación y la respuesta inmune. El análisis de la microbiota intestinal reveló cambios significativos en la composición de su composición, especialmente en el intestino posterior, sugiriendo una posible falta de capacidad de regular la respuesta inmune y de modular la colonización de bacterias patógenas tras un largo periodo de alimentación con esta dieta. Por otro lado, el análisis del proteoma de la mucosa intestinal también mostró un claro impacto sobre distintos procesos biológicos relacionados con el mantenimiento del homeostasis intestinal y de la integridad epitelial. Por el contrario, no se observó un impacto de la sustitución de la harina de pescado a nivel de expresión génica o del proteoma cuando se incorporaba a la dieta una fuente de proteína marina complementaria, aunque sí que se observaron algunos signos menores de inflamación. Por último, se desarrolló un sistema ex vivo para estudiar la respuesta inflamatoria e inmune de la mucosa intestinal a la presencia de distintas bacterias, y se realizó un ensayo preliminar en dorada para evaluar el efecto de la dieta sobre esta respuesta. En resumen, en este trabajo se ha realizado una evaluación extensa y detallada de los efectos a nivel intestinal de la inclusión de altos niveles de proteína vegetal en la dieta para doradas de engorde. Los resultados indican que las alteraciones en la capacidad inmune, la homeostasis y la microbiota intestinal aparecían solo cuando la proteína procedía exclusivamente de fuentes vegetales, y podrían explicar la mayor mortalidad registrada con esta dieta.
Malgrat que la utilització d'alts nivells de proteïna vegetal en pinsos per a dorades en la fase d'engreixament s'ha aconseguit amb èxit en quan al creixement, aquestes dietes encara s'associen amb freqüència amb efectes negatius en l'eficiència nutricional i la capacitat immunitària. L'intestí és l'òrgan on es produeix la primera interacció entre el peix, els nutrients de la dieta i les bactèries de l'ambient, i juga un paper fonamental en la digestió dels nutrients i en la resposta inflamatòria i immune. Aquesta tesi doctoral es centra en l'impacte de diferents dietes experimentals amb un alt nivell de proteïna vegetal, i especialment, en l'avaluació de l'estat de l'intestí de les dorades d'engreixament alimentades durant un llarg període amb alts nivells de substitució de farina de peix. Els distints canvis observats a nivell intestinal es van descriure mitjançant l'ús de distintes estratègies, com l'anàlisi de la digestibilitat i la retenció dels aminoàcids, de l'excreció d'amoni i de l'activitat enzimàtica, dels canvis histològic o de l'expressió de gens relacionats amb la funció i el manteniment de l'estructura intestinal, així com tècniques òmiques per a l'anàlisi del proteoma i de la microbiota intestinal. Es van assatjar diferents nivells de substitució de farina de peix, però l'impacte de les dietes amb substitució completa, bé complementada amb subproductes d'origen marí o suplementada amb aminoàcids lliures sintètics, va rebre major atenció. La substitució completa de la farina de peix va tenir un efecte lleugerament negatiu sobre el creixement i l'eficiència digestiva i nutritiva de la dorada d'engreixament, encara que l'impacte era major quan els peixos eren alimentats des de la fase de juvenils amb aquesta dieta. La digestibilitat i el nivell de síntesis de proteïna es va veure alterada, encara que no s'observaren diferències significatives en l'activitat dels enzims digestius. No obstant, l'impacte de les fonts vegetals quan s'eliminaven per complet les fonts de proteïna marina de la dieta era especialment crític en la supervivència dels peixos. En l'intestí d'aquests peixos sols s'observaren xicotets indicis d'inflamació a nivell histològic, però també es va observar una disminució l'expressió de gens involucrats amb el procés inflamatori i la resposta immune. L'estudi de la microbiota intestinal va revelar canvis significatius en la composició, especialment a l'intestí posterior, suggerint una possible falta de capacitat de regular la resposta immunitària i de modular la colonització per part de patògens després d'un llarg període d'alimentació amb aquesta dieta. D'altra banda, l'anàlisi del proteoma de la mucosa intestinal també va mostrar un impacte clar sobre diferents processos biològics relacionats amb el manteniment de l'homeòstasi intestinal i de la integritat de l'epiteli. Per contra, no es van observar un impacte de la substitució de la farina de peix a nivell d'expressió gènica o proteoma quan s'incloïa a la dieta una font complementària de proteïna d'origen marí, encara que sí que s'observaven alguns signes d'inflamació. Per últim, es va desenvolupar un sistema ex vivo per avaluar la resposta inflamatòria i immune de la mucosa intestinal davant la presència de diferents bactèries, i es va realitzar un assaig preliminar per determinar l'efecte de la dieta sobre aquesta resposta. En resum, en aquest treball s'ha realitzat una avaluació extensa i detallada dels efectes a nivell intestinal de la inclusió d'alts nivells de fonts de proteïna vegetal a les dieta per a les dorades d'engreixament. Els resultats indiquen que les alteracions en la capacitat immunitària, l'homeòstasi i la microbiota intestinal eren observades solament quan la proteïna era exclusivament obtinguda de fonts vegetals, i podrien explicar la major mortalitat observada amb aquesta dieta.
Although the inclusion of plant protein sources at high levels in aquafeeds for on-growing gilthead seabream has been successfully achieved on gilthead seabream in terms of growth, these diets are still associated to detrimental effects in feed efficiency and immune capacity. The intestine is the organ where takes place the first interaction of the host with dietary antigen or environmental bacteria, and plays a major role in the digestion of nutrients and the inflammatory and the immune response. The present PhD thesis focus on the impact of classical formulated high plant protein diets on fish performance, but especially, on evaluation of the intestinal status in on-growing fish long-term fed with high levels of fishmeal replacement. Changes at intestinal level were characterized by using different approaches, including protein and amino acid digestibility and retention and ammonia excretion, digestive enzyme activity, histology, expression of genes related with inflammation, immunity, structure and digestion, but also using whole tissue-level techniques for the analysis of the impact on proteome and gut microbiota. Different levels of fishmeal replacement were assayed, although the impact of diets with total replacement, complemented by inclusion of alternative marine by-products or supplemented by free amino acids, received greater attention. Total fish replacement produced a negative but minor impact on the growth and nutritive and digestive performance of on-growing gilthead seabream. Nevertheless, when fish were fed from juvenile stage with plant protein based diets, a higher negative impact in growth terms was noticed. Digestibility and metabolic use of amino acids was altered, but no differences were observed in the digestive enzyme activities. Nonetheless, feeding fish with total dietary fishmeal replacement by plant protein without any marine protein source was especially critical for survival rate. In these fish, gut histological assessment only revealed minor alterations related with an inflammatory response, but gene expression assay showed a down-regulation of several genes involved in the inflammatory and immune response. Moreover, a drastic change in the microbiota composition was observed, especially at the hindgut, revealing a possible lack of capacity to regulate a defensive response and to face with pathogen colonisation after a long-term coupling with these diet. Likewise, gut mucosa proteome analysis also suggests an impact on biological processes related with the maintenance of gut homeostasis and the epithelial integrity. In contrast, total fishmeal replacement did not induce alterations at transcript or proteomic level when diet was complemented with marine ingredients, although some minor inflammatory signs were reported. On the other hand, an ex vivo system to study the inflammatory and immune response of the gut mucosa to the presence of different bacteria was developed, and a preliminary assay evaluating the impact of the diet on this response was performed. To sum up, present works represents a wide assessment at intestinal level of the effects of including plant protein sources at high levels in aqua feeds for on-growing gilthead seabream. Results indicate that alterations in the immune capacity, the gut homeostasis and the microbiota were observed when protein was exclusively provided by plant sources, and could explain the higher mortality reported with this diet.
Estruch Cucarella, G. (2018). ASSESSMENT OF THE LONG-TERM IMPACT OF HIGH PLANT PROTEIN DIETS ON THE INTESTINAL STATUS OF THE ON-GROWING GILTHEAD SEA BREAM (Sparus aurata, L.) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/113063
TESIS

No presente estudo foram efetuados três ensaios. No primeiro, foram comparados os efeitos de teores crescentes de proteína metabolizável (PM), de acordo com o NRC (2001) para vacas lactantes mantidas em pastagens de capim Elefante. Os aumentos em PM foram obtidos com o aumento da proporção de farelo de soja na ração. Foram utilizadas 12 vacas, delineadas em quadrado latino 3 x 3 com quatro repetições, durante 60 dias de avaliação. Não foi observado efeito (P>0,05) sobre a produção de leite e leite corrigido para 3,5% de gordura, teores e produção de gordura, proteína e sólidos totais. Houve aumento linear (P<0,05) nos teores de nitrogênio uréico no leite (11,17; 13,17; 15,63 mg dL-1) e no plasma (18,57; 19,93; 21,99 mg dL-1). No segundo ensaio, foram avaliados os efeitos de dois diferentes intervalos entre desfolhas (95% de interceptação de luz pelo dossel – T1 e 27 dias fixos – T2) das pastagens de capim Elefante sobre o desempenho lactacional de vacas leiteiras. Foram utilizadas oito vacas lactantes, delineadas em cross-over, durante 80 dias. Os dados das pastagens foram analisados através de delineamento inteiramente casualizado com medidas repetidas no tempo. Foi observado maior (P<0,05) altura do dossel em pré (1,03 e 1,21m) e pós-pastejo (0,62 e 0,71m), interceptação de luz pelo dossel (95,47 e 97,91%), teor de fibra em detergente ácido (35,88 e 37,05%) e fibra em detergente neutro (65,08 e 66,99%). Não houve efeito dos tratamentos (P>0,05) sobre a massa de forragem em pré (6.270 e 6.310 kg de MS ha-1) e pós-pastejo (3.580 e 3.850 kg de MS ha-1). Houve tendência de maior produção de leite (16,72 e 14,09 kg dia-1), produção de gordura (0,64 e 0,54 kg dia-1), lactose (0,72 e 0,58 kg dia-1) e de sólidos totais (2,04 e 1,70 kg dia-1) para o T1 em comparação com o T2. No terceiro estudo, foram avaliados os efeitos de três estratégias de suplementação protéica nas rações (isoprotéicas) com cana-de-açúcar para vacas em lactação, em dois níveis de produção, 18 kg dia-1 (T1, T2 e T3) e 10 kg dia-1 (T4, T5 e T6). No T1 e T4, foi usado o teor de 1 kg de uréia para cada 100 kg de cana-de-açúcar in natura, no T2 e T5 as rações foram formuladas com teores ajustados de PM, enquanto no T3 e T6 havia teores excessivos de PM, conforme o NRC (2001), através do aumento em farelo de soja e redução na uréia. Para a análise dos dados foi utilizado o delineamento em quadrado latino 3 x 3 com três replicações. Não houve efeito dos tratamentos (P>0,05) sobre o consumo de matéria seca, produção de leite, teor de gordura, proteína e sólidos totais. Também não houve efeito dos tratamentos (P>0,05) sobre os teores de nitrogênio uréico no leite (13,42; 13,26; 14,03 e 13,62; 13,48; 14,12 mg dL-1) e no plasma (19,03; 19,22; 20,02 e 19,23; 19,32 e 20,12 mg dL-1), para ambos os grupos avaliados.
In the present study three trials were conducted. Trial 1: Three concentrates with increasing metabolizable protein (MP) contents were fed to lactating dairy cows grazing Elephant grass. Extra soybean meal was fed to increase MP in the diet beyond NRC (2001) recommendation. Twelve cows were used in a 3 x 3 latin square design, replicated four times, for 60 days. There were no effects (P>0.05) of treatments on milk yield, 3,5% fat corrected milk, on fat, protein and total solids contents and yields. Milk urea nitrogen and plasma urea nitrogen concentrations increased linearly (P<0.05)(11.17; 13.17; 15.63 and 18.57; 19.93; 21.99 mg dL-1) with increasing concentrate crude protein content. Trial 2: Two different intervals between defoliation (95% of light interception – T1 and 27 days fixed – T2) of Elephant grass pasture were compared for lactating dairy cows. Eight cows were used in a cross-over design during 80 days. The pasture data were analyzed in a complete random design with time repeated measurements. The sward heights pre-grazing (1.03 and 1.21m), and post-grazing (0.62 and 0.71m), light interception (95.47 and 97.91%), acid detergent fiber (35.88 and 37.05%) and neutral detergent fiber (65.08 and 66.99%) were higher for T2 compared to T1. Forage mass pre-grazing (6270 and 6310 kg DM ha-1) and post-grazing (3580 and 3850 kg DM ha-1) were not affected by treatments (P>0.05). There were tendencies for higher milk yield (16.72 and 14.09 kg day-1), fat yield (0.64 and 0.54 kg day-1), lactose yield (0.72 and 0.58 kg day-1) and total solids yield (2.04 and 1.70 kg day-1) for T1 in comparison with T2. Trial 3: Three strategies for protein adequacy in sugarcane based diets were compared for lactating dairy cows producing 18 kg milk day-1 (T1, T2 and T3), or 10 kg of milk day-1 (T4, T5 and T6). In treatment 1 (T1 and T4) urea was added to the diets in the dose of 1% of sugarcane (as fed), as traditionally done in Brazil. In treatment 2 (T2 and T5), diets were formulated according to NRC (2001) to be adequate in MP. In treatment 3 (T3 and T6), MP was fed in excess of NRC (2001) recommendation. All the three diets were isonitrogenous. Increasing soybean meal and decreasing urea in the diets was done to increase MP. Eighteen dairy cows, separated in two groups (10 and 18 kg milk-1 day-1) with nine cows each, were used during sixty days, in a 3 x 3 latin square design replicated three times. There were not effects of treatments (P>0.05) on DMI, milk yield, fat contents and yields, protein contents and yields and total solids contents and yields. There were not effects of treatments (P>0.05) on milk urea nitrogen (13,42; 13,26; 14,03 e 13,62; 13,48; 14,12 mg dL-1) and plasma urea nitrogen (19.03; 19.22; 20.02 and 19.23; 19.32 e 20.02 mg dL-1).

Tese de Doutoramento em Ciências Veterinárias, especialidade em Ciências Biológicas e Biomédicas
Carbohydrate-active enzymes (CAZymes) include a range of enzymes that, in nature, make, break or modify glycosidic bonds. CAZymes act on highly recalcitrant polysaccharides, such as cellulose and hemicellulose, and often exhibit a modular architecture including catalytic domains fused through flexible linker regions to non-catalytic domains such as carbohydrate-binding modules (CBMs). In some anaerobic bacteria these enzymes can associate in high molecular mass multi-enzyme complexes termed cellulosomes. Cellulosomal organisms express a vast repertoire of plant cell wall degrading enzymes and constitute a promising source for the discovery of novel CAZymes. Presently, an exponential accumulation of genomic and metagenomic information is observed while the identification of the biological role of both genes and proteins of unknown function is sorely lacking. In addition, for most of the known CAZymes, structure and/or biochemical characterization is missing. In this study we have developed innovative approaches for the discovery of novel CAZymes in cellulosomal bacteria and provide a detailed biochemical characterization of some of those enzymes. A high-throughput platform was designed for cloning, expression and production of recombinant cellulosomal proteins in Escherichia coli, aiming at looking for novel cellulosomal CAZymes encoded in the genomes of Clostridium thermocellum and Ruminococcus flavefaciens. As a result, a series of novel prokaryotic expression vectors (pHTP) were constructed to allow ligation-independent cloning with high levels of soluble recombinant protein production. In addition, to allow total automation of the procedure, both novel cell culture media and protein purification methods have been established. The platform allowed the production of 184 cellulosomal proteins of unknown function that after the implementation of an enzyme discovery screen lead to the discovery of a novel family of α-Larabinofuranosidases. In order to achieve recombinant soluble expression in E. coli, novel fusion tags were designed and incorporated into pHTP-derivatives. Both Rf1 and Rf47 tags, derived from cellulosomal components, were shown to display a high capacity to enhance protein solubility, as fusion proteins containing both these tags were expressed at high levels and in the soluble form in E. coli. CBMs were confirmed to affect the catalytic activity of appended CAZymes, as it was illustrated by the CBM32 of CtMan5A. This work revealed that members of family 35 CBM have the capacity to bind β-mannose-containing polymers. The biochemical characterization of PL1A, PL1B and PL9 reported here describes the pectinolytic activity expressed by C. thermocellum cellulosome. These enzymes are appended to CBMs that display considerable ligand promiscuity. The application of β- glucanases in animal feed supplementation was tested either in the free state or while associated in mini-cellulosomes. This study revealed that β-1,3-1,4-glucanases and not β-1,4-glucanases are necessary to improve the nutritive value of barley-based diets for broilers. In addition, it was shown that mini-cellulosomes designed to improve the efficacy of exogenous enzymes used for feed supplementation require an effective mechanism to protect linker regions from proteolytic cleavage.
RESUMO - Descoberta de novas enzimas celulossomais de bactérias anaeróbias que degradam hidratos de carbono - As enzimas que na natureza degradam os hidratos de carbono (CAZymes) são capazes de construir, quebrar ou modificar ligações glicosídicas. Estas enzimas actuam sobre polissacáridos complexos e recalcitrantes, como a celulose e a hemicelulose, e apresentam geralmente uma estrutura modular, podendo incluir módulos catalíticos fundidos através de sequências de ligação a domínios não catalíticos, sendo os mais comuns os módulos de ligação a hidratos de carbono (CBMs). Em algumas bactérias anaeróbias, estas enzimas podem associar-se em complexos multi-enzimáticos de elevada massa molecular designados de celulossomas. Os organismos que produzem estes complexos apresentam um vasto repertório de enzimas envolvidas na degradação da parede celular vegetal e constituem um bom ponto de partida para a descoberta de novas CAZymes. Actualmente, verifica-se uma crescente acumulação de informação genómica e metagenómica a um ritmo superior à capacidade de identificação da função biológica de uma plêiade de genes e proteínas de funções desconhecidas. Para além disso, para a maioria das CAZymes já conhecidas, não foi ainda efectuada uma caracterização estrutural e/ou bioquímica. Neste estudo foram desenvolvidas metodologias inovadoras para a descoberta de novas CAZymes em bactérias celulossomais, bem como se procedeu a uma caracterização bioquímica detalhada para algumas destas enzimas. Desenvolveu-se uma plataforma de alta capacidade para a clonagem, expressão e produção de proteínas celulossomais recombinantes em Escherichia coli, tendo como objectivo descobrir novas CAZymes codificadas nos genomas de Clostridium thermocellum e Ruminococcus flavefaciens. Como resultado, foi construída uma nova série de vectores de expressão (pHTP) a fim de sustentarem um método de clonagem independente de ligação. Para possibilitar a total automatização do processo foram desenvolvidos novos meios de cultura celulares e métodos de purificação de proteínas adaptados a um esquema de produção de alta capacidade. A pesquisa de novas enzimas nos módulos celulossomais de função desconhecida possibilitou a descoberta de uma nova α-L-arabinofuranosidase em R. flavefaciens, que se constitui como a enzima fundadora de uma nova família de CAZymes. A fim de potenciar a solubilidade de proteínas recombinantes em E. coli, foram desenhadas novas tags de fusão, as quais foram incorporadas em vectores derivados do pHTP. Tanto as tags Rf1 como Rf47, derivadas de componentes celulossomais, mostraram possuir uma capacidade elevada para potenciar a solubilidade de proteínas, uma vez que as proteínas de fusão contendo quer uma quer outra destas tags foram produzidas na forma solúvel em níveis mais elevados do que com parceiros de fusão anteriormente descritos. Confirmou-se que os CBMs afectam a actividade catalítica das CAZymes associadas, tal como ilustrado pelo CBM32 da CtMan5A. Este trabalho forneceu indicações de que os CBMs membros da família 35 têm a capacidade de se ligarem a polímeros de β-manose. A caracterização bioquímica das PL1A, PL1B e PL9 aqui descrita constituiu o primeiro relato de actividade pectinolítica no celulossoma de C. thermocellum. Estas enzimas podem estar associadas a CBMs que revelam pouca especificidade de ligação aos substratos. Testou-se a aplicação de β-glucanases na suplementação alimentar animal, tanto como enzimas isoladas, como associadas em mini-celulossomas. Os dados apresentados aqui revelam que são as β-1,3-1,4-glucanases e não as β-1,4-glucanases as enzimas responsáveis por melhorar o valor nutritivo de dietas à base de cevada para frangos. Por outro lado, os resultados mostram que a eficácia dos mini-celulossomas para melhorar o desempenho das enzimas exógenas usadas na suplementação alimentar requer um mecanismo eficaz para proteger as regiões de ligação entre os componentes celulossomais da degradação por proteases.

El presente trabajo de investigación tiene como propósito determinar y analizar los factores que influyeron en las exportaciones peruanas de alimentos para animales de la industria acuícola con destino a Ecuador dentro del marco de la CAN entre los años 2010 al 2019. Para establecer ello, se ha determinado la selección de tres variables a estudiar con el fin de procurar responder si las normas de origen, la creación de comercio y las medidas sanitarias y fitosanitarias, todas ligadas a la relación entre Perú y la Comunidad Andina en términos comerciales sobresaliendo las preferencias arancelarias del producto elegido en dirección a Ecuador y los protocolos sanitarios aplicados, han estimulado un mayor intercambio comercial entre los dos países en los periodos considerados anteriormente. Del mismo modo, también se ha precisado la evaluación de organizaciones involucradas que afectan el nivel y el desarrollo de las exportaciones peruanas con destino a Ecuador. Para la presente investigación, la información recopilada se obtuvo de distintas fuentes como SUNAT, SIICEX y Trademap que posibilitaron el acceso a las estadísticas de exportaciones de la partida mostrando, de igual manera, a las empresas que las componen con sus respectivos registros. Sumado a ello, a través de distintas entrevistas con los actores primordiales implicados se logró obtener mayor información, conocimiento y apreciación en relación a los factores propuestos en esta investigación. En virtud de lo cual, todos los datos recolectados se analizarán bajo el Software SPSS Statistics v. 25 y Atlas.ti 8.
The purpose of this research work is to determine and analyze the factors that influenced Peruvian exports of animal feed from the aquaculture industry to Ecuador within the framework of the CAN between the years 2010 to 2019. To establish this, the selection of three variables to study has been determined in order to try to answer whether the rules of origin, the creation of trade and sanitary and phytosanitary measures, all linked to the relationship between Peru and the Andean Community in trade terms, highlighting the tariff preferences of the chosen product to Ecuador and the certifications obtained, have stimulated greater trade between the two countries in the periods considered above. In the same way, the evaluation of organizations involved that affect the level and development of Peruvian exports to Ecuador has also been specified. For the present investigation, the information collected was obtained from different sources such as SUNAT, SIICEX and Trademap, which made it possible to access the tariff heading's export statistics showing, in the same way, the companies that compose them with their respective records. Added to that, through different interviews with the main actors involved, it was possible to obtain more information, knowledge and appreciation in relation to the factors proposed in this research. By virtue of it, all the collected data will be analyzed under the SPSS Statistics v. 25 and Atlas.ti 8 Software.
Tesis