Dissertations / Theses on the topic 'Broiler feeds'

Assignment (MPhil)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: The aim of this study was to evaluate the performance and profitability of different dietary specifications for broiler chickens slaughtered at 35 days of age. Two trials were performed to evaluate different production parameters. The results of these trials were compared to the predicted results of the EFG broiler model. No carcass data were available for the two trials mentioned above. Therefore, in order to evaluate the accuracy of the broiler model when predicting carcass characteristics, two published data sets (Leeson et al., 1996a) were used. Predicted and actual values were compared, evaluated and discussed. Two broiler trials were performed. In Trial One the amino acid density decreased throughout the range of three treatments from prestarter to finisher diets. In Trial Two the amino acid density decreased only in the four finisher diets. The main difference between predicted and actual results was the response to body weight. The model predicted a steady increase in feed intake to compensate for the lower dietary specifications while body weight did not change significantly. This increase in feed intake seems to be enough to maintain body weight. Trial birds also increased their feed intake as dietary amino acid density decreased, but this compensation seemed to be too low to maintain body weight compared to the control diet. The birds may find it easier to compensate when they have time to adapt to the specification. There is evidence in the literature that birds need seven days to adapt their feed intake to a lower feed specification (Leeson et al., 1996a). It can be speculated that the trial birds started to loose body weight due to a lower amino acid intake in this period. The model seems to adapt feed intake immediately after a change in diet specification. The simulation on literature data lead to the following conclusions: 1) Broilers posses the capacity to increase their feed intake with at least 65% should finisher diets with lower amino acid and energy concentrations be supplied. If only the energy concentration of finisher diets were decreased, the increase in feed intake will be around 30%. (see Table 16 and 23) 2) The accurate prediction of feed intake from the given dietary specification has a major influence on the accuracy of the prediction of broiler performance. 3) Amino acid density and DLys:ME ratio plays a significant role in the control and prediction of feed intake. The EFG broiler model is based on sound scientific principles. The model is comprehensive and can be used for a wide range of environmental and management conditions as well as dietary conditions. The nutritionist can use the model with confidence to assist in practical feed formulation. The actual strength of the model lies in the time and money being saved compared to practical trials.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om die prestasie en winsgewendheid van braaikuikens te bepaal wanneer voere met verskillende digthede tot op 35 dae gevoer word. Twee eksperimente is uitgevoer om produksieresultate te evalueer. Die resultate van hierdie eksperimente is met die voorspelde waardes uit die EFG simulasie-model vergelyk. Aangesien geen karkasdata vir bogenoemde eksperimente beskikbaar was nie, is twee gepubliseerde datastelle gebruik om hierdie deel van die model te evalueer (Leeson et al., 1996a). Twee braaikuiken eksperimente is uitgevoer. Eksperiment Een het uit drie behandelings bestaan waarvan die aminosuur-konsentrasie vanaf dag een tussen behandelings verskil het. In Eksperiment Twee het die aminosuur-konsentrasie net in die vier afrondingsdiëte verskil. Liggaamsmassa op 35 dae het die grooste verskil tussen voorspelde- en werklike waardes getoon. Beide voorspelde en werklike innames het in albei eksperimente verhoog soos wat aminosuur-konsentrasie afgeneem het. Voorspelde liggaamsmassa het egter konstant gebly terwyl werklike data 'n afname in liggaamsmassa getoon het. Dit bleik dat die voorspelde toename in innames voldoende was om massa te onderhou terwyl die voëls in werklikheid nie genoeg gekompenseer het nie. Leeson et al., 1996a het tot die gevolgtrekking gekom dat braaikuikens minstens sewe dae benodig om hul voeriname by 'n nuwe spesifikasie aan te pas. So 'n stadige aanpassing kan daartoe lei dat energie- en aminosuur-inname daal indien 'n dieet met laer spesifikasie gevoer. Dit sal daartoe lei dat die kuikens liggaamsmassa verloor. Uit die literatuur simulasies is die volgende afleidings gemaak: 1) Braaikuikens besit die vermoeë om voerinname in die afrondingstyd met minstens 65% te verhoog indien 'n afrondingvoer met laer amiosuur- asook energiekonsentrasie gevoer word. Indien net die energiekonsentrasie verlaag word, sal die inname met sowat 30% verhoog. 2) Die akkurate voorspelling van inname is krities vir die akkurate voorspelling van produksieparameters. 3) Aminosuur-digtheid en DLys:ME speel 'n belangrike rol in die beheer en voorspelling van voerinname by braaikuikens. Die EFG braaikuikenmodel is op suiwer wetenskaplike beginsels geskoei. Die model is omvattend en kan vir 'n wye reeks van omgewings- en bestuurstoestande asook dieet-spesifikasies gebruik word. Die voedingkundige kan die model met vertroue gebruik om met praktiese voerformulering by te staan. Die model kan die formuleerder baie tyd spaar aangesien praktiese eksperimente ingeperk kan word.

A study was conducted using commercial broiler breeders with the males fed a diet containing, either 120/0 or 140/0 protein and body weight maintained at either 900/0 or 1000/0 of that recommended by the primary breeder (fed separately), or allowed to eat from the female feeders (controls). Female feeders in the separately fed pens were equipped with especially designed grills, which denied access to the males. The male feeder in these pens was elevated so that females were denied access.

Males fed separately (body weight 90% or 1000/0, and dietary protein 120/0 or 140/0) had a significantly higher percentage fertility (4.20/0) than males allowed to eat with the females. No differences in percentage fertility were found among the four separately fed groups. No differences were noted in percentage hatch of fertile eggs among any of the treatment groups.

Males eating from the female feeders had significantly heavier body weights and testes weights at 65 weeks of age than breeder males in the separately fed, groups. Mean body weights were 3819g and 4773g at 35 weeks of age, and 4192g and 5443g at 65 weeks of age for males eating separately and eating with the females, respectively. Furthermore, males in the control group had significantly larger breast angle measurements when compared with the separately fed males. No differences were observed in foot scores and semen concentration among males in the various treatment groups.

Master of Science

The primary cereal grain used in poultry feed worldwide is maize. An understanding of how and where broiler chickens digest native starches, this being the major energy component of maize, and the influence that exogenous xylanase has on this process, is essential when optimising nutrient utilisation of a diet. In this project, both in vitro and in vivo models were used to understand broiler digestion of starches in different maize-based diets: native maize starch, maize grit and maize-soy with or without xylanase (Econase XT 25 at 100 g/t; 18,100 BXU/kg). An in vitro model to simulate the digestive tract of broilers using a ball milling technique to mimic the chicken gizzard was designed to investigate differences in the digestion of starches between the various diets. Reduced starch crystallinity and particle size of the diet was shown when samples were ball milled in HCl-pepsin, compared to roller mixed samples, leading to a greater glucose release when these samples were incubated with pancreatin. The maize-soy diet gave the greatest glucose release with pancreatin, with native maize starch giving the lowest, indicating that the processing of diets prior to digestion as well as the surrounding food matrix can impact on the digestion of starches in feed. In all in vivo trials, starch fraction measurements and SEM imaging of digesta collected from the gizzard, upper and lower small intestine, revealed the progression of starch granule digestion through the tract. Despite birds being starved prior to feeding, broilers ingested little of the native maize starch diet. Nonetheless, predominantly intact granules were evident in the gizzard, with signs of amylase attack becoming apparent in the small intestine. Following starvation, starch granules were still observed throughout the tract of birds, suggesting the presence of resistant starches. Higher digesta pH values were observed when birds were fed a maize-soy diet which gave pH 3.56, 6.70, 7.70 for the gizzard, and upper and lower small intestine, respectively, compared to pH 2.47, 6.49, 7.34 for the maize grit diet, an effect that could potentially impact on digestive processes. In feeding trials with broilers, inclusion of xylanase into the maize-soy diet and feeding on a single occasion revealed no apparent difference in the matrices surrounding the starch granules in digesta. This suggested that xylanase may be working indirectly in vivo through some physiological change in the digestion mechanism rather than direct action on the feed. To test this hypothesis, birds were fed xylanase for different lengths of time before slaughter. Peptide YY concentration in the blood was higher during the first few weeks of supplementation, with longer periods of supplementation nulling this effect, suggesting that xylanase may be acting through a prebiotic mechanism. RT-qPCR results revealed a trend towards an increase in glucose transporter (GLUT2 and SGLT1) expression at 2 and 3 weeks of xylanase supplementation, respectively. This also correlated to an increase in glucose concentration in the blood from 3 weeks of xylanase inclusion, suggesting a greater absorption capacity of birds. These results may indicate a potential mechanism of xylanase action in maize-based diets, although further work is required to confirm these findings.

This study was undertaken to respond to the requirement of the emerging Thai broiler producers to comply to international standards in product anatoxin contamination. Field work was established with farmers to improve their animal husbandry. A standard methodology for anatoxin analysis was also established. The efficiency of four commercial clean-up columns for the determination of anatoxins in broiler mixed feeds were compared and contamination levels of anatoxins in broiler mixed feeds marketed in Thailand were determined. The four clean-up columns used were from Varian, Vicam, Romer and Rhdne. Two types of broiler feed, manufactured by the Charoen Pokphand (CP.) company and the Betagro company were tested. Samples tested were standard anatoxin solution, spiked broiler mixed feed and naturally contaminated feed. All samples were cleaned-up using the four columns followed by quantification of anatoxins by HPLC. Comparative column efficiency was determined. Feed collected from the field over a 42 day period was examined for anatoxin contamination using the Varian column. There was variation in the efficiency of columns when different types of samples were used. There was also a difference in the column efficiency when different sources of feed samples were applied. The relative column efficiency for the clean-up of the standard anatoxin solution was, in descending order, Varian, Vicam, Rhone and Romer columns. Based on the SAS analysis by CRD, the Varian column gave the best anatoxin recoveries. Anatoxin recoveries from the four different columns were determined with spiked Betagro feed samples, Efficiency was in descending order, Varian, Vicam, Romer and Rhdne columns. For the spiked CP. feed the order was Vicam, Varian, Rhone and Romer columns, respectively. There was a significant difference in column efficiency. The Varian and Vicam columns were significantly more efficient than the Rhone and Romer columns. The Varian and Vicam columns had the highest relatively efficiencies for both brands of broiler mixed feeds. The natural contamination of anatoxin determined in two brands of feed using the Varian columns was 14.41 to 18.40 p.p.b. for the CP. feed and 11.33 to 18.18 p.p.b. for the Betagro feed when samples were collected from the delivery sacks. When samples were collected from feeding bins the range was 18.49 to 20.39 p.p.b. for the CP. feed and 17.30 to 20.67 p.p.b. for the Betagro feed. Feed samples were of an acceptable quality and all broilers were normal. As the anatoxin contamination levels detected in broiler mixed feeds were low, their relationship to changes in broiler physiology could not be determined. The field study on broiler quality in 1998 indicated some abnormalities on the broilers but there was no such problem on the broiler's quality in 2000, which may be accounted by the instigation of the improved animal husbandry.

This study was conducted with the aim to investigate the efficacy of exogenous enzyme supplementation in releasing metabolisable energy in broiler feeds. Two performance trials were conducted during this study. Effects were measured in terms of the body weight gain, feed intake, feed conversion ratio, mortality and production efficiency factor in broilers. Correct interpretation and practical application of the positive effects of exogenous enzyme supplementation to commercial broiler feeds can aid nutritionists to develop nutritionally balanced broiler feeds at lower costs. The negative effects of anti-nutritional factors in broilers feeds can be greatly reduced with the strategic use of exogenous enzyme addition to the feed. In the first performance trial, four treatment feeds were fed to broilers. The Positive control feed was a balanced diet, formulated according to standard nutrient specifications used by Daybreak Farms, with only the metabolisable energy marginally lower than the standard to ensure that energy was the first limiting nutrient. Nutrient specification met or exceeded recommendations by the NRC (1994). A Negative control feed, similar to the Positive control, was formulated with 0.35 MJ ME / kg feed less than the Positive control. An Avizyme treatment and a Hemicell treatment were formulated similar to the Negative control, with the addition of 0.05% Avizyme and 0.0125% Hemicell to the respective treatments. The addition of Avizyme and Hemicell to the respective treatments was hypothesised to release an additional 0.35 MJ ME / kg feed. Four thousand three hundred and twenty day-old Ross 788 chicks were randomly divided into four treatment groups, each with eight replicates and 135 birds per replicate for the first seven days. After seven days birds were reduced to 126 birds per replicate. In the second performance trial, five treatment feeds were fed to broilers. The Positive control feed was a balanced diet, formulated according to standard nutrient specifications used by Daybreak Farms, with only the metabolisable energy marginally lower than the standard to ensure that energy was the first limiting nutrient. Nutrient specification met or exceeded recommendations by the NRC (1994). Results of the first performance trial indicated that more than the hypothesised 0.35 MJ ME / kg feed was being released from the feed with exogenous enzyme addition. Subsequently, the difference in metabolisable energy between the Negative control and Positive control treatments were increased for the second trial. A Negative control feed, similar to the Positive control, was formulated with 0.45 MJ ME / kg feed less than the Positive control. An Avizyme treatment and a Hemicell treatment were formulated similar to the Negative control, with the addition of 0.05% Avizyme and 0.0125% Hemicell to the respective treatments. A Combination treatment was formulated similar to the Negative control, with the addition of both 0.05% Avizyme and 0.0125% Hemicell to the feed. Seven thousand five hundred and sixty day-old Ross 788 chicks were randomly divided into five treatment groups, each with 12 replicates and 126 birds per replicate. For both trials, birds were housed in environmentally controlled houses with a similar lighting schedule and ad libitum access to feed and water. Body weights, feed intake and mortality were recorded weekly for the duration of the five week performance trials. The data was statistically analysed, using the general linear model function in SAS (Statistical Analysis Systems, 1989; Statistical Analysis Systems, 1994). Fischer’s protected test was used for the post hoc multiple comparison test. Repeated tests were included in the model. The confidence interval was set at 95%. Initial body weight was tested as a covariate in all the analyses. Incorrect dosing of the trial feeds during the first performance trial prevented the evaluation of the treatments for the entire 35 day period. The difference between the Positive control and the Negative control treatments were not large enough to enable the exact determination of the amount of metabolisable energy that the Avizyme released in the feed. It could, however, be concluded that Avizyme addition to a broiler feed increased broiler production efficacy. The Avizyme treatment was contributed at least 0.35 MJ ME / kg feed during the trial released more than 0.35 MJ ME / kg feed during the extended starter phase of the trial. The above mentioned conclusions served as a motivation to increase the metabolisable energy difference between the Positive control and the Negative control treatments for the next performance trial. Addition of Hemicell to the feed contributed 0.35 MJ ME / kg feed over a five week growing period. With the second performance trial, the Avizyme and Hemicell treatments released an additional 0.45 MJ ME / kg feed, supported by broiler production variables similar to the Positive treatment. The Combination treatment was shown to release more than 0.45 MJ ME / kg feed and significantly increased broiler performance. It was concluded that the combination of Hemicell and Avizyme in a broiler ration had a positive synergistic effect on each other in the young broiler, indicating that exogenous enzymes could be more effective in younger broilers. Although exogenous enzymes resulted in the release of a significant amount of additional metabolisable energy in the feed, the addition of these enzymes should undergo economical evaluation to ensure that the addition of these enzymes is viable under commercial circumstances. Addition of Avizyme with a calculated energy contribution of 0.35 MJ ME / kg and 0.45 MJ ME / kg to the feed realised an income over feed cost (IOFC) of 25 c / kg live weight and 4 c / kg live weight, respectively, during the five week period. The Hemicell treatment showed a negative IOFC (suggesting that Hemicell inclusion will decrease profit) of 24 c / kg live weight during the first four weeks of the first production trial and an IOFC of 2 c / kg live weight during the five week period of the second trial. The combination of both enzymes in the feed returned an IOFC of 16 c / kg live weight. In general the income over feed cost was the highest during the starter phase because of a higher efficacy of exogenous enzyme addition in younger broilers.
Dissertation (MSc(Agric))--University of Pretoria, 2012.
Animal and Wildlife Sciences
unrestricted

Barred Rock chickens were offered diets that had been pelleted at 55° or 85°C. In an 8-week feeding trial, the subjects receiving pellets processed at the higher temperature experienced significant (P ≤ .05) weight gain over those receiving the diet processed at 55°C. Although feed consumption for this treatment increased as well, the difference was not significant (P ≤ .05). Chemical investigation revealed that metabolizable energy and bioavailability of lysine of both heat treatments were similar. Starch availability as measured by in vitro enzyme susceptibility, however, was lowered by increased heat application. In a second experiment, the feeding behavior of 12-16 week old cockerels offered diets of varying particle size, resulted in significant (P ≤ .05) increases in feed consumption rate and therefore decreases in total feeding activity for birds offered pellets and crumbles as compared to mash and reground pellets. No differences were noted in meal size, meal frequency, interval between meals, or total consumption. In a parallel experiment, no differences were noted in the behavioral parameters of birds receiving diets pelleted at 55, 70, or 85°C of similar density and particle size. Mash controls, however, experienced significantly (P ≤ .05) decreased consumption rate and concurrent increase in feeding activity. The beneficial effects experienced with pelleting can therefore be attributed to the reduction in total feeding activity that allows an increased proportion of net energy to be utilized in support of growth.
M.S.

A procedure was developed to examine factors contributing to skin strength of meat-type chickens. Skin breaking strength was initially measured in lines of chickens divergently selected for high (H) and low (L) juvenile body weight, their reciprocal crosses (HL and LH), and an F₂ generation derived from HL and LH matings. Skin of chicks from the LL line was weakest, that from the HH and LH matings strongest, and that from HL and F₂ matings was intermediate. Percentage heterosis for breaking strength was significantly positive while percentage recombination was not significant. Skin breaking strength and protein, fat, moisture, and total collagen concentrations of skin from the breast, thigh, and back of male and female commercial broilers were then examined in response to diets containing relatively wide or narrow ratios of calories to protein (C:P). Comparisons were made at 28, 42, and 56 days of age. Chickens fed diets containing wider C:P ratios had weaker skin than those fed diets with narrower C:P ratios, with the differences being greater at older than at younger ages. Males had stronger skin than females. Among body sites, breast skin was stronger than thigh skin with that from the back being intermediate in strength. Skin breaking strength did not appear to be consistently associated with either the protein, fat, or collagen concentrations in the skin. Skin from broiler chicks fed diets with differing C:P ratios was also examined histologically. Males had stronger and thinner skin than females, with the differences in thickness due primarily to differences in the thickness of the hypodermis. Regardless of sex, feeding diets containing wider C:P ratios resulted in weaker and thicker skin. The thicker skin was associated with an increase in the thickness of the hypodermis and a decrease in the thickness of the dermis and epidermis. With the exception of differences between back and thigh skin, increases in breaking strength occurring between skin from different sites were associated with a reduction in total skin thickness and in the thickness of the hypodermis. It was concluded that increased hypodermis thickness and/or decreased thickness of the dermis and epidermis reduced skin strength. Two experiments were conducted in which skin strength was examined in relation to heat stress and supplemental ascorbic acid. In the first experiment, chicks fed diets containing 0 or 100 mg of ascorbic acid per kg of diet were subjected to either a constant ambient temperature of 23C, a constant ambient temperature of 32C, or a treatment consisting of 32C from 1600 to 1200 hr and 400 from 1200 to 1600 hr (32/400). Both heat stress and supplemental ascorbic acid tended to increase collagen concentrations in the skin, but differences in breaking strength were inconsistent in response to these treatments. Supplemental ascorbic acid, however, partially alleviated reductions in body weight due to heat stress but did not decrease body temperatures of heat-stressed chicks. In the final experiment, diets containing either 0, 200, or 400 mg/kg of supplemental ascorbic acid were fed to chicks maintained at ambient temperatures of 23 and 34C. Contrary to previous observations, ascorbic acid failed to ameliorate the depressive effect of heat stress on body weight. Supplemental ascorbic acid tended to reduce adrenal, bursa of Fabricius, and spleen weights but had no effect on heterophil and lymphocyte numbers or ratios. Adrenal ascorbic acid concentrations were not significantly affected by supplemental ascorbic acid and plasma ascorbic acid levels were inconsistent among treatment groups. Neither supplemental ascorbic acid nor heat stress significantly influenced skin strength. It was concluded that supplemental ascorbic acid was not beneficial in improving skin strength in commercial broiler chicks.
Ph. D.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011.
Includes bibliography.
ENGLISH ABSTRACT: A growth and digestibility trial was conducted comparing the effect of an experimental enzyme at three different inclusions. A negative control containing no enzyme additions and a positive control containing a proven commercial enzyme were compared in a maize-soybean diet noting the performance of broilers and the digestibility of the grower feed. The commercial enzyme was a granular product with a xylanase activity of 38114.29 nkat/g and the second enzyme (ABO374) was a liquid experimental product with a xylanase activity of 1426.86 nkat/ml. Five diets were used i.e. control basal diet without enzyme supplementation (negative control), basal diet supplemented with the commercial enzyme (positive control) and three basal diets supplemented with the test enzyme at various inclusion levels (ABO 50, ABO 100 and ABO 200). The positive control was supplemented with 200 g/ton of the commercial enzyme; ABO 50 was supplemented with ABO374 at an inclusion level of 2671 ml/ton, ABO 100 with 5342 ml/ton and ABO 200 with 10684 ml/ton. Supplementation with the test enzyme (ABO 50) significantly improved BW at 23 days of age by 4.6 % (1107.4 g vs 960.96 g) and at 37 days of age by 3.2 % (2311.75 g vs 2237.81 g) over the negative control. Body weight gain for the total period of the trial was significantly improved by 3.24 % (64.32 g/bird/day vs 62.24 g/bird/day) the test enzyme supplementation (ABO 50) when compared to the negative control. During the starter phase, test enzyme supplementation (ABO 50) led to an improvement of 4.58 % (1.25 vs 1.31) in FCR in comparison with the negative control. The FCR for the total trial obtained by the test enzyme supplementation was significantly lower than the FCR obtained by the positive control. The highest EPER obtained for this trail was by the test enzyme supplemented diets and this was significantly higher than the EPER obtained by the positive control. It is clear from this growth trial that the test enzyme (ABO374) at an inclusion level of 2671 ml/ton outperformed the commercial enzyme and that it has the potential to improve the production performance of broilers on a maizeSBM based diet. The total tract digestibility method and total collection method was used to conduct the digestibility trial. The total tract digestibility method measures the difference between the amounts of each nutrient consumed from the amounts of each nutrient excreted in faeces. Only apparent digestibilities are reported for the digestibility trial. Apparent digestibility does not take the endogenous protein fraction in the faeces into account. The endogenous protein fraction is derived from digestive enzymes and proteins from the intestinal walls that are secreted into the digestive tract. The grower negative control, positive control, ABO 50, ABO 100 and ABO 200 diets used in the production trial were also used in the digestibility trial. Supplementation with the test enzyme showed no significant improvements on the apparent digestibility of dry matter, organic material, ash, crude protein, metabolisable energy or crude fibre. No significant improvements in the apparent digestibility of the amino acids (threonine, arginine, valine, lysine, methionine, cysteine and isoleucine) were noticed either and thus the digestibility of the grower feed were not influenced by the addition of enzymes due to the supplementation of the test enzyme ABO374. Pelletisation of the grower diets could have lead to the inactivation of the enzyme due to the high temperature at which pelletisation takes place. Another possible reason why enzyme supplementation did not increase nutrient digestibility, may be that the breakdown of non-starch polysaccharides by the enzymes led to an increase in the concentration of oligosaccharides in the small intestine of the birds, thus leading to the decrease in nutrient absorption Key words: body weight, body weight gain, feed conversion ratio, European production efficiency ratio, maize, soybean meal, apparent digestibility, dry matter, organic material, ash, crude protein, metabolisable energy, crude fibre, xylanase, pellitisation.
AFRIKAANSE OPSOMMING: ‘n Groei en vertering studie was uitgevoer om die effek van ‘n eksperimentele ensiem wat teen drie verskillende insluitingsvlakke by ‘n basale dieët bygevoeg is te vergelyk met ‘n negatiewe kontrole wat geen ensiem bevat het nie en met ‘n positiewe kontrole wat ‘n kommersiële ensiem bevat in ‘n mielesojaboon oliekoek dieët op die produksie vermoë van braaikuikens en die verteerbaarheid van die groei voer. Die kommersiële ensiem was ‘n granulêre produk met ‘n xylanase aktiwiteit van 38114.29 nkat/g en die eksperimentele ensiem (ABO374) was ‘n vloeistof produk met ‘n xylanase aktiwiteit van 1426.86 nkat/ml. Vyf diëte was gebruik nl. ‘n basale dieët met geen ensiem byvoeging (negatiewe kontrole), basale dieët met die byvoeging van die kommersiële ensiem (positiewe kontrole) en drie basale diëte wat met die byvoeging van die eksperimentele ensiem teen drie verskillende insluitings vlakke (ABO 50, ABO 100 and ABO 200). Die kommersiële ensiem was by die positiewe kontrole bygevoeg met ‘n insluitings vlak van 200 g/ton, ABO374 was bygevoeg by ABO 50 met ‘n insluitings vlak van 2671 ml/ton, ABO 100 met 5342 ml/ton en ABO 200 met 10684 ml/ton. Die byvoeging van die eksperimentele ensiem (ABO 50) het gelei tot die betekenisvolle verbetering van die liggaamsmassa van die voëls by die ouderdom van 23 dae met 4.6 % (1107.4 g teenoor 960.96 g) en by die ouderdom van 37 dae met 3.2 % (2311.75 g teenoor 2237.81 g) teenoor die negatiewe kontrole. Liggaams massa toename vir die hele periode van die studie was betekenisvol verhoog met 3.24 % (64.32 g/kuiken/dag teenoor 62.24 g/kuilen/dag) met die byvoeging van die eksperimentele ensiem (ABO374) teenoor die negatiewe kontrole. Voeromset verhouding was betekenisvol verbeter met 4.58 % (1.25 teenoor 1.31) toe die kommersiële ensiem bygevoeg was teenoor die negatiewe kontrole. Die hoogste europese produksie effektiwiteits verhouding wat verkry is vir die hele studie periode is deur die byvoeging van die eksperimentele ensiem (ABO374). Hierdie groei studie dui dus duidelik aan dat die gebruik van die eksperimentele ensiem (ABO374) baie beter resultate as die kommersiële ensiem opgelewer het teen ‘n insluitings vlak van 2671 ml/ton, dus het ABO374 die potensiaal om die produksie potensiaal van braaikuikens op ‘n mielie-sojaboonoliekoek dieët te verbeter. Die totale spysverteringskanaal verteerbaarheid metode was gebruik om die verteerbaarheid studie uit te voer. Die totale spysverteringskanaal verteerbaarheid metode meet die verskil tussen die nutriënt inhoud van die voer en die nutriënt inhoud van die mis. Slegs die skynbare verteerbaarheid van nutriënte word vir hierdie verteerbaarheidstudie gerapporteer. Skynbare verteerbaarheid sluit nie die endogene proteïenfraksie wat afkomstig is van verteringsensieme of die proteïene afkomstig vanaf die spysverteringskanaal se intestinale wande af in nie. Die negatiewe kontrole, positiewe kontrole, ABO 50, ABO 100 en ABO 200 groei diëte gebruik in die produksie studie is gebruik vir die verteringsstudie. Die byvoeging van die eksperimentele ensiem het geen betekenisvolle resultate opgelewer ten opsigte van droë materiaal, organiese material, as, ru-proteïen, ru-vesel of metaboliseerbare energie nie. Daar was ook geen betekenisvolle resultate opgelewer wanneer die eksperimentele ensiem bygevoeg was nie ten opsigte van die verteerbaarheid vir aminosure (treonien, arginien, valien, metionien, sisteïen en isoleosien) nie en dus is die verteerbaarheid van die groeivoer glad nie beïnvloed deur die byvoeging van die eksperimentele ensiem nie. Die verpilling van die groei voer mag dalk gelei het tot die inaktivering van die eksperimentele ensiem deur dat dit blootgestel was aan hoë temperature. ‘n Ander moontlike rede vir die mislukking van die ensiem kon gewees het dat die afbreking van die nie-stysel polisakkariedes deur die ensiem kon gelei het tot die verhoging van die oligosakkariede konsentrasie in die laer spysverterings kanaal en dus kon dit lei tot ‘n verhoogde deurvloeitempo, gevolg deur ‘n afname in die absorpsie van nutriënte. Sleutel woorde: Liggaamsmassa, liggaamsmassa toename, voeromsetverhouding Europese produksie effektiwiteits verhouding, mielie, sojaboonoliekoek, skynbare verteerbaarheid, droëmaterial, organiesematerial, as, ru-proteïen, ru-vesel, metaboliseerbare energie, verpilling.

Corrigenda inserted behind title page. Bibliography: leaves 275-306. The pattern of body growth and intestinal development of an Australian strain of broiler chicken, the Steggles x Ross (F1) in response to different diets was studied. Five experiments were designed to examine the pattern of growth and mechanisms involved. In four other experiments, the mechanisms underlying the gross response of the broiler chicks to dietary ingredients, anti-nutritive factors and growth enhancers were examined. Results indicated that a rapid development of the small intestine preceded significant overall body growth. Body growth would, however, depend more on the various physiological events such as those related to mucosal growth and renewal, digestive enzyme function, and nutrient transport. Some of the differences observed in productivity of broiler chickens on different diets were traced to events at the intestinal level.

Thesis (M. Tech.(Agriculture: Animal Production)) - Central University of technology, Free State, 2012
A 42-day feeding trial involving 180 day old broiler chicks was carried out at Glen Agric Institute ARC poultry section to study the effects of whole hatchery waste meal (WHWM) as an alternative in broiler diets. In this study whole hatchery waste meal (WHHW) replaced fish meal (FM), protein for protein, in broiler diets at 0, 10, 20, and 30% levels. One hundred and eighty broiler chickens were grouped, 45 birds per treatment which were further replicated 3 times (15 birds per replicate) in a completely randomized design. Feed and water supply were offered to birds ad libitum while standard management practices were meticulously adopted. Samples of the two test ingredients were sent to a lab for chemical analysis and the results indicated that FM had higher content of crude protein (73.18%) while that of WHWM was 4226. The calcium phosphorus ratio was 16.6:1 for WHWM as against 1.5:1 in the FM. The results also indicated a higher content of Ash% and Ether extract for WHWM (18.12) and (23.94) respectively. The higher ash content could be due to the high content of eggshell at the time of processing. At the end of the feeding trial broiler performance, blood, carcass characteristics and the economic benefit of using WHWM in broiler diets were determined. Blood and meat samples were collected and sent to the pathology laboratory at the University of the Free State, Bloemfontein for hematological and meat characteristics analysis. Results for broiler performance showed that broilers fed diet 2 had highest values for feed intake (118.25g/bird/day), weight gain (50.16g/bird/day) and daily protein intake (29.08g/bird/day) while those fed with diet 3 were superior in the efficiency of feed conversion (2.31). The highest value of abdominal fat 1.12% was observed in birds fed diet 2. The highest live mass was observed in birds fed diets containing no WHWM (2.83), while non significant difference were observed in live mass of birds fed diet 1, 3 and 4. Broilers fed control diet had highest mean values for eviscerated weight (2.20kg) and dressing percentage (77.86%). Blood samples were sent for analysis of White blood cells (WBC), Red blood cells (RBC) and Haemoglobin (HGB), Hematogrit (HCT), Mean corpuscular volume (MCV), Mean corpuscular haemoglobin (MCH) and Mean corpuscular haemoglobin concentration (MCHC). The results showed marginal variations in blood parameters. White blood cell counts were higher for birds fed control diet (519.59 x 103/1) than those fed WHWM (484.93 X 103/1). Non significant differences (P > 0.05) were observed on the HGB of all treatment groups including the control group. RBC counts of T1-T3 were not significantly different from each other but statistically significantly different from T4 (30% WHWM). The highest value of 2.67 106/ mm3 was observed in birds fed a higher level of WHWM. High RBC and HGB counts in the birds fed WHWM are an indicative of higher oxygen carrying capacity. The HCT and MCH results showed nonsignificant differences between T1, T3 and T4, except T2 which was significantly different from the other treatment groups. The MCV values for T1-T4 were 132.58, 126.47, 129.15 and 128.15 10'15L respectively. The highest and lowest values were recorded on T1 and T2 respectively. The feed costs decreased with an increase in the level of WHWM in broiler diets. The lowest feed cost/kg weight gain of R8.69 recorded for broilers fed on diet three. This agrees with several studies which documented the use of hatching waste in poultry diet as means of reducing feed cost (Babiker et al 1991; Abiola, 1999; Abiola, 2000; Abiola and Onunkwor 2004). It can be concluded that 10% of FM can be replaced with WHWM in broiler diets without adverse effects on growth, hematological and carcass traits.

Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2005.
The extrusion and dehulling of sweet blue lupins (Lupinus angustifolius, cultivar Wonga) and the expansion of full-fat canola seed were evaluated in terms of their effect on the nitrogen corrected apparent metabolizable energy (AMEn) value and broiler performance.

This study was conducted to assess the effect of including Tenebrio molitor larvae (T. molitor L) as a protein source in different diets on broiler performance, carcass characteristics and meat quality. A total of 144 day-old Cobb-500 chicks were randomly allocated into three treatment groups, each was allocated 16 birds and reared in 9 identical pens. Experimental diets used were as follows: T1 Control (no T. molitor L inclusion); T2 and T3 contained levels of T. molitor L at 5 percent and 10 percent of dry matter (DM) intake, respectively. Body weights (BW), average daily gain (ADG), feed intake (FI), and Feed conversion ratio (FCR) were measured for the 1st experimental chapter. For the second experimental chapter; live weights (LW) of broilers were recorded before slaughter and thereafter carcass weights (CW), meat yield (weights of breast, thigh, drumstick and wing) were recorded. The dressing percentage (DP percent) was also calculated. Breast muscles were sampled for meat pH and colour measurements. The LW of birds from T1 (0 percent T. molitor L) were significantly different (P<0.05) from both T2 (5 percent T. molitor L) and T3 (10 percent T. molitor L) which were similar to each other, with T2 exhibiting the highest live weights (2166g) and the control treatment exhibiting the lowest live weights (2018.3g). In CW, T1 was significantly different (P<0.05) from T2 while it was similar (P>0.05) to T3. The dressing percent of T1 was significantly different (P<0.05) from T2 and T3 which were similar to each other, with T2 having the highest dressing percentage (78, 2 percent) and T1 having the lowest DP percent (66 percent). The breasts in T2 were significantly higher and different (P<0.05) from both T1 and T3 which were similar to each other. The drumsticks in T3 were significantly different (P<0.05) from T1 while they were similar to T2 with values with T2 having highest values. After 45 minutes of slaughter, a significant difference (P<0.05) was observed in L⃰ among all treatments. In redness (a⃰), T3 was significantly different from T1 but was similar to T2 and all treatments in this study exhibited a darker red meat, with T3 muscles exhibiting darker red colour than the other treatments. Similar results were observed in yellowness (b⃰), where the breast muscles from T3 were more yellow than the other treatments. After 24 hours of slaughter, T2 L⃰ values were significantly different (P<0.05) from both T1 and T3 which were similar to each other. It was also found that the broiler chickens given diet with no T. molitor L inclusion (T1) had lower values of BW, FI, ADG and FCR throughout the experiment than those that were in T2 and T3 with 5 percent and 10 percent T. molitor L inclusion levels, respectively. However, it was also found that although broilers with 5 percent T. molitor L inclusion (T2) in their diet had high ABW and ADG than the broilers with 10 percent T. molitor L inclusion (T3), the T3 birds compared favourably to T2 birds as they required low feed intake to reach the same slaughter weight due to high FCR. It was, therefore, concluded that T. molitor L meal can be incorporated into the diets of broilers to produce heavy birds either at 5 or 10 percent. However, although 5 percent T. molitor L inclusion yields heavier carcasses, the 10 percent T. molitor L inclusion compared favourably to 5 percent inclusion since it required low feed intake to reach the same slaughter weights and there were slight differences on meat quality attributes between the two treatments.Thus T. molitor L at 10 percent inclusion levels was the best inclusion level to enhance broiler growth performance, carcass yield, meat yield and meat quality.

Thesis (M.Sc. (Animal Production)) -- University of Limpopo, 2014
Two experiments were conducted to determine the effects of supplementing diets with effective microorganisms on intake, growth and carcass characteristics of Ross 308 broiler chickens. The first experiment determined the effect of supplementing diets with effective microorganisms on performance of unsexed Ross 308 broiler chickens aged one to three weeks. Two hundred unsexed day-old chicks were randomly assigned to five treatments with four replications, each replication having ten birds. A complete randomized design was used. The chickens were fed a grower diet supplemented with 0 (EM0), 30 (EM30), 50 (EM50), 70 (EM70) or 100 (EM100) ml of effective microorganisms per litre of water. Effective microorganism supplementation did not improve (P>0.05) diet and metabolisable energy intakes of the chickens. Effective microorganism supplementation reduced (P<0.05) growth rate and live weight of the chickens. Poorer (P<0.05) feed conversion ratios were observed in chickens supplemented with effective microorganisms. However, effective microorganism supplementation improved (P<0.05) crude protein retention of the chickens. Supplementation with effective microorganisms reduced (P<0.05) mortality rate of the chickens from 10 to 0 %. The second experiment determined the effect of supplementing diets with effective microorganisms on performance of male Ross 308 broiler chickens aged 22 to 42 days. The chickens were randomly allocated to five treatments with four replications, each replication having 10 birds. The chickens aged 21 days, weighing 474 ± 2g, were allocated to the treatments in a complete randomized design. The chickens were fed a grower diet supplemented with 0 (EMM0), 30 (EMM30), 50 (EMM50, 70 (EMM70) or 100 (EMM100) ml of effective microorganisms per litre of water. Effective microorganism supplementation did not improve (P>0.05) intake, DM digestibility, metabolisable energy, feed conversion ratio, fat pad weight and meat sensory attributes of the chickens. Effective microorganism supplementation reduced (P<0.05) growth rate, live weight and carcass weight of the chickens. However, effective microorganism supplementation improved (P<0.05) crude protein retention and crude protein content of meat of the chickens. Supplementation with effective microorganisms reduced (P<0.05) mortality of the chickens from 5 to 0 %. v It is concluded that effective microorganism supplementation to the diets of Ross 308 broiler chickens reduced growth rate and live weight of the chickens. However, effective microorganism supplementation improved crude protein retention and crude protein content of the meat of broiler chickens. Supplementation with effective microorganisms reduced mortality of the chickens to zero.

Thesis (MSc. (Animal Production)) -- University of Limpopo, 2016
This study was conducted to determine the effect of supplementing diets with antimicrobials and effective microorganisms on productivity and carcass characteristics of Ross 308 broiler chickens. The study consisted of two parts. The first part determined the effect of antimicrobial and effective microorganism (EM) supplementations on growth performance of unsexed Ross 308 broiler chickens aged one to 21 days. A complete randomized design was used and 150 unsexed day-old chicks with an initial weight of 42 ± 2g were randomly assigned to five different treatments which were replicated 3 times with each replicate having 10 chicks. The five grower diets had the same nutrients (20% CP and 12MJ/kg) but different supplementation levels of 0g oxytetracycline and 0ml EMs/l of water (UAM0EM0), 0.01g oxytetracycline (UAM0.01EM0), 30ml EMs/l of water (UAM0EM30), 50ml EMs/l of water (UAM0EM50) and 100ml EMs/l of water (UAM0EM100). A quadratic regression model was used to determine dietary effective microorganism supplementation levels for optimal feed intake and live weight of Ross 308 broiler chickens. A linear model was used to determine the relationship between dietary effective microorganism supplementation levels and metabolisable energy intakes. Antimicrobial and effective microorganism supplementations did not have any effect (P>0.05) on growth rate, feed conversion ratio and mortality. Antimicrobial supplementation improved (P<0.05) feed intake and live weight of the chickens. Supplementation with 50ml of EMs/l of water improved (P<0.05) feed intake. Supplementation with 50 or 100ml of EMs per litre of water increased (P<0.05) ME intake of the chickens. Effective microorganism supplementation levels of 72.25 and 48.29ml of drinking water optimized feed intake and live weight, respectively. The second part of the experiment determined the effect of antimicrobials and effective microorganisms on productivity, blood, carcass characteristics and meat quality of male Ross 308 broiler chickens aged 22 to 42 days. The chickens were randomly allocated to five treatments with three replications, each having six chickens. A total of 90 male chickens, with the initial live weight of 452 ± 3g were allocated to the treatments in a complete randomized design. The chickens were fed a grower diet supplemented with 0g oxytetracycline and 0ml EMs/l of water (MAM0EM0), 0.01g oxytetracycline (MAM0.01EM0), 30ml EMs/l of water (MAM0EM30), v 50ml EMs/l of water (MAM0EM50) and 100ml EMs/l of water (MAM0EM100). Antimicrobial and effective microorganism supplementation did not have effect (P>0.05) on feed intake, growth rate, live weight, ME intake, blood glucose and mortality. Poorer (P<0.05) feed conversion ratio was observed with the supplementation of antimicrobial. Blood glucose levels were optimized at an effective microorganism supplementation level of 29.00ml of EM/l of drinking water (Figure 4.05). Supplementing diets with antimicrobials and effective microorganisms did not have effect (P>0.05) on crop, gizzard, proventriculus and large intestine pH values of male chickens. However, supplementation with of 100ml of EMs per litre of drinking water reduced (P<.0.05) the pH of ileum. Effective microorganism supplementation level of 85.00ml per litre of drinking water optimized the crop pH value. Antimicrobial and effective microorganism supplementations did not have influence (P>0.05) on gizzard, proventriculus, small intestine, caecum, large intestine, liver and heart weights of male chickens at 42 days. Effective microorganism supplementation level of 50ml per litre of drinking water reduced (P<.0.05) crop weight. Antimicrobial and effective microorganism supplementations did not have effect (P>0.05) on whole gastro-intestinal tract (GIT), small intestine and caecum length of the chickens. Antimicrobial supplementation reduced (P<0.05) the length of large intestine. Effective microorganism supplementation levels of 41.00, 45.50 and 85.00ml per litre of drinking water optimized crop weights and caecum and large intestine lengths, respectively. Antimicrobial and effective microorganism supplementations did not have any influence (P>0.05) on live weight, carcass weight, breast weight, drumstick weight ad thigh weight. Similarly, antimicrobial and effective microorganism supplementations did not have influence on meat tenderness, juiciness and flavour. There were no antibiotic and effective microbe residues in the meat. It is, therefore, concluded that effective microorganism supplementation did not have much effect on production parameters, carcass characteristics and meat quality of Ross 308 broiler chickens.

Thesis (MA. Agric. (Animal Production)) -- University of Limpopo, 2014
This study determined the effect of carrot meal supplementation on productivity and carcass characteristics of Arbor acres broiler chickens aged one to six weeks. Experiment I determined the effect of carrot meal supplementation on productivity of Arbor acre broiler chicks aged one to 21 days. Two hundred unsexed Arbor acre broiler chickens were randomly assigned to five treatments with five replicates, each replicate having ten birds. A completely randomized design was used in the first experiment. The treatments were 0 (UA0), 20 (AU20), 50 (AU50), 75 (AU75) or 100 (AU100) g of carrot meal supplementation per kg DM feed. Quadratic equations were used to determine levels of carrot meal supplementation for optimal feed intake, metabolisable energy intake and nitrogen retention of Arbor acre broiler chickens aged one to 21 days. Linear equations were used to determine relationships between carrot meal supplementation and productivity variables. Dietary carrot meal supplementation had no (P>0.05) effect on growth rate, live weight and feed conversion ratio of unsexed Arbor acre broiler chickens aged one to 21 days. Carrot meal supplementation, however, improved (P<0.05) metabolisable energy intake and nitrogen retention of the chickens. Dietary metabolisable energy intake and nitrogen retention of the chickens were optimized at different carrot meal supplementation levels of 40.5 and 53.57 g/kg DM feed, respectively. No chicken deaths were recorded. Experiment II determined the effect of carrot meal supplementation on productivity and carcass characteristics of female Arbor acre broiler chickens aged 22 to 42 days. The chickens were randomly allocated to five treatments with five replicates, each having 10 birds, in a completely randomized design. The supplementation levels were 0 (FA0), 20 (FA20), 50 (FA50), 75 (FA75), or 100 (FA100) g of carrot meal per kg DM feed. Quadratic equations were used to determine levels of carrot meal supplementation for optimal feed intake, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention of broiler chickens aged 22 to 42 days. Linear equations were used to determine relationships between carrot meal supplementation and production variables. Dietary carrot meal supplementation had no (P>0.05) effect on growth rate, live weight and carcass parts of female Arbor acre broiler chickens aged 22 to 42 days. Carrot meal supplementation improved (P<0.05) feed intake, feed conversion ratio, metabolisable energy intake and nitrogen retention of Arbor acre broiler chickens aged vi 22 to 42 days. Dietary feed intake, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention were optimized at different dietary carrot meal supplementation levels of 52.8, 63.8, 38.0, 42.0 and 44.3 g/kg DM feed, respectively. Dietary carrot meal supplementation had no effect (P>0.05) on tenderness and flavour of female Arbor acre broiler meat. Broiler chickens on diets supplemented with 20, 50 or 100 g of carrot meal per kg DM feed produced meat with better (P<0.05) juiciness values than those of meat from chickens not supplemented with dietary carrot meal and those supplemented with 75 g/kg DM feed. There was a positive relationship between carrot meal supplementation and chicken meat juiciness. It is concluded that carrot meal supplementation improved (P<0.05) metabolisable energy intake and nitrogen retention of unsexed Arbor acre broiler chickens aged one to 21 days. However, carrot meal supplementation had no effect (P>0.05) on growth rate, live weight and feed conversion ratio of unsexed Arbor acre broiler chickens aged one to 21 days. Carrot meal supplementation improved (P<0.05) intake, feed conversion ratio, metabolisable energy and nitrogen retention of female Arbor acre broiler chickens aged 22 to 42 days. However, carrot meal supplementation did not (P>0.05) improve growth rate and live weights of the chickens.

Thesis (MSc. Agriculture (Animal Production)) -- University of Limpopo, 2014
Two experiments were conducted to determine the effect of moringa seed meal supplementation on productivity and carcass characteristics of Ross 308 broiler chickens. The first experiment determined the effect of moringa seed meal supplementation on productivity of Ross 308 broiler chickens aged one to 21 days. Two hundred and fifty unsexed day-old Ross 308 broiler chicks were randomly allocated to five dietary treatments, replicated five times, and each replication having 10 chickens. A completely randomized design was used. The chickens were fed on a grower diet supplemented with 0 (M0), 5 (M5), 10 (M10), 15 (M15) and 20 (M20) g of moringa seed meal/bird/day. Moringa seed meal supplementation had no effect (P>0.05) on feed intake, metabolisable energy intake, nitrogen retention, feed conversion ratio and live weight of unsexed Ross 308 broiler chickens. Moringa seed meal supplementation improved (P<0.05) growth rates of unsexed Ross 308 broiler chickens aged one to 21 days. A moringa seed meal supplementation level of 13.3 g/kg DM feed optimized growth rate of Ross 308 broiler chickens aged one to 21 days. The second experiment determined the effect of moringa seed meal supplementation on productivity and carcass characteristics of female Ross 308 broiler chickens aged 22 to 42 days. The chickens weighing 558 ± 10 g/bird were randomly allocated to five treatments with five replications having 10 birds. The chickens, aged 21 days, were allocated to the treatments in a completely randomized design. The chickens were fed on a grower diet supplemented with 0 (FM0), 5 (FM5), 10 (FM10), 15 (FM15) and 20 (FM20) g of moringa seed meal per kg DM. Moringa seed meal supplementation had no effect (P>0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake, carcass weight, breast meat weight, abdominal fat pad weight, liver weight, heart weight, thigh weight, meat flavour, juiciness and tenderness of female Ross 308 broiler chickens. However, moringa seed meal supplementation improved (P<0.05) nitrogen retention and gizzard weights of female Ross 308 broiler chickens. vi It was concluded that moringa seed meal supplementation improved growth rate of unsexed Ross 308 broiler chickens aged one to 21 days. Similarly, moringa seed meal supplementation increased nitrogen retention and gizzard weights of female Ross 308 broiler chickens aged 22 to 42 days.

Three potential probiotics, Lactobacillus acidophilus, Lactobacillus casei and the fungus Scytalidium acidophilum were prepared in different ways. They were evaluated for their effects on performance and immune responses in broiler chickens in two 6-week trials. In the first trial, probiotics were orally administered at the ages of day 1 and day 8. There were no differences between live and disrupted cells. However, cobalt-containing cells had improved effects numerously in comparison with non cobalt-containing cells. As a result, these three disrupted probiotics, each in two different concentrations, were sprayed onto a mash basal feed before pelleting in the second trial. Improved feed intake (up to 6%) and body weight gain (up to 7%) were observed in all probiotic treatments. The anti-KLH IgA and IgG titers of probiotic-treated chickens were not significantly different from the negative controls in both trials. In summary, disrupted and cobalt-containing probiotics were proved to enhance the performance of broiler chickens and are promising for commercial application. In addition, a new fungal mycelium, Scytalidium acidophilum, was suggested to be a good probiotic to improve the growth of broilers.

Thesis (MSC. Agriculture (Animal Production)) --University of Limpopo, 2014
Two experiments were conducted to determine the effect of moringa seed meal supplementation on productivity and carcass characteristics of Ross 308 broiler chickens. The first experiment determined the effect of moringa seed meal supplementation on productivity of Ross 308 broiler chickens aged one to 21 days. Two hundred and fifty unsexed day-old Ross 308 broiler chicks were randomly allocated to five dietary treatments, replicated five times, and each replication having 10 chickens. A completely randomized design was used. The chickens were fed on a grower diet supplemented with 0 (M0), 5 (M5), 10 (M10), 15 (M15) and 20 (M20) g of moringa seed meal/bird/day. Moringa seed meal supplementation had no effect (P>0.05) on feed intake, metabolisable energy intake, nitrogen retention, feed conversion ratio and live weight of unsexed Ross 308 broiler chickens. Moringa seed meal supplementation improved (P<0.05) growth rates of unsexed Ross 308 broiler chickens aged one to 21 days. A moringa seed meal supplementation level of 13.3 g/kg DM feed optimized growth rate of Ross 308 broiler chickens aged one to 21 days. The second experiment determined the effect of moringa seed meal supplementation on productivity and carcass characteristics of female Ross 308 broiler chickens aged 22 to 42 days. The chickens weighing 558 ± 10 g/bird were randomly allocated to five treatments with five replications having 10 birds. The chickens, aged 21 days, were allocated to the treatments in a completely randomized design. The chickens were fed on a grower diet supplemented with 0 (FM0), 5 (FM5), 10 (FM10), 15 (FM15) and 20 (FM20) g of moringa seed meal per kg DM. Moringa seed meal supplementation had no effect (P>0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake, carcass weight, breast meat weight, abdominal fat pad weight, liver weight, heart weight, thigh weight, meat flavour, juiciness and tenderness of female Ross 308 broiler chickens. However, moringa seed meal supplementation improved (P<0.05) nitrogen retention and gizzard weights of female Ross 308 broiler chickens. vi It was concluded that moringa seed meal supplementation improved growth rate of unsexed Ross 308 broiler chickens aged one to 21 days. Similarly, moringa seed meal supplementation increased nitrogen retention and gizzard weights of female Ross 308 broiler chickens aged 22 to 42 days.

This investigation was conducted in the rural community of Cuambo, located in the northeast of the province of Imbabura, in the Mira river basin of Salinas parish, at 1530 meters above sea level and with an average temperature of 19.5° C. The main objective of this investigation was to analyze the effect of using amaranth (Amaranthus) leaf flour in the creation of feeds for broiler chickens. The field work occurred during 12 months and consisted of two phases: A. Creation of the feed: This proceeded from the cultivation, cutting, and drying of amaranth until the obtaining of the flour and later the feed, with the respective formulation and acquisition of primary materials. B. Broiler chicken production: This occurred in the coop of the community's school, previously prepared for taking in the chicks. The study lasted 8 weeks. A completely random design (CRD) with five treatments and four repetitions per treatment was used, with 10 chickens per experimental unit. ANOVA analysis and Tukey and orthogonal comparisons were applied. The factor under study was the percentage of amaranth leaf flour in a basic diet. The treatments were as follows: T0 = Control diet for broiler chickens T1 = 16.7% amaranth leaf flour T2 = 35% amaranth leaf flour T3 = 54% amaranth leaf flour T4 = 78% amaranth leaf flour Analyzed variables: Weekly weight increase, Weekly food conversion, Accumulated food conversion, Total food consumption, Efficiency index, Yield, Skin pigmentation at the end of the treatments, Organoleptic analysis, Mortality, Economic analysis. From the results obtained, we conclude that the feed from treatment 1 (T1) is the best because it gave the most efficient results in terms of weight increase, food conversion, efficiency index, yield, and production cost. In the organoleptic analysis, T2 received more points regarding appearance, color, and texture; T1 received the best points in odor. The most acceptable treatments are T2 and T1, with the most points. In production cost, T4 was the least expensive, but it is not recommended for use because the chickens had poor results in the studied variables.

This study was designed was to determine the effects of additive supplementation of Moringa oleifera leaf meal on growth performance, digestibility, digestive organ size, intestinal integrity, bone ash content and bone breaking strength, as well as meat yield and quality of broiler chickens. A total of 2400 day-old unsexed Cobb-500 broiler chicks were randomly allocated to 5 treatment groups: T1, positive control, 668 g/ton Salinomycin and 500 g/ton Albac; T2, T3 and T4 contained graded levels of MOLM at 1 percent, 3 percent and 5 percent of dry matter (DM) intake, respectively; and T5, a negative control (0 percent additives) in a complete randomized design experiment. Except for week one, FI and FCR was highest (P < 0.05) in T4 birds; while T1 birds had the highest FI in the period of 22 to 27d (P < 0.05). Throughout the production period, birds supplemented with MOLM had the highest BW (P < 0.05) than the birds fed the control diets. Feed intake (FI) and feed conversion ratio (FCR) among treatments was highest (P < 0.05) in T4 birds during the period of 8 to 14 d; and was highest (P < 0.05) for T1 birds in the period of 22 to 27d. Protein efficiency ratio (PER) and energy utilization efficiency (EEU) ratios were statistically significant among treatments (P < 0.05). However, dietary treatments had no effect (P > 0.05) on the weights of the heart, liver, spleen, or the gizzard, although the bursa for T2 birds was the lightest (P < 0.05); while gizzard erosion score was highest in T2 birds. All of the nutrients measured, except for fat, had negative intercepts that were significantly different (P < 0.05) from zero, indicating the presence of endogenous fecal losses. Tibiae length (TL) was highest in T2. The dried defatted weight (DW) was heaviest (P < 0.05) for T3 (11.20 ± 0.347) and T5 (11.08 ± 0.328). A positive correlation (r = 0.667; P < 0.01) between TW and DW was observed. There were no dietary effects on bone breaking strength (BBS), but T1 tibiae had highest resistance to breaking force (T1 > T4 > T3 > T2 > T5). Calcium was highest (P < 0.05) in T1; and lowest inT2 and T5. Phosphorus levels were lowest (P < 0.05) in T1; and highest (P < 0.05) in T5 compared. The highest Ca: P ratio was obtained in T4 (P < 0.05); while the ash percent was highest (P < 0.05) in T1. Drip loss increased as L* values increased; and a negative correlation was observed between L* and pH. On D1, C18: 0 and C22 in T2, while C15:0 was highest in T4. On D1, C20:2, C20:3n6 and C22:6n3 were highest in T2 (P < 0.05); T4 had the highest C18:3n6 (P < 0.05), while C20:2 was highest in T5 (P < 0.05). The P/S ratio on D1 was highest in T4; while n-6/n-3 was highest in T1; and n-3 was highest in T3. On D8, the n-3 was highest in T1 (P < 0.05). Results of the current study show that supplementation of M. oleifera leaf at additive levels of up to 5 percent of the bird’s DMI does have the potential to influence the bird performance without any detrimental effects on nutrient utilization, bird health, bone strength and/or meat quality, which can be concluded that MOLM enhanced the bird’s genetic potential for optimal productivity.

Thesis (MScAgric)--Stellenbosch University, 2008.
ENGLISH ABSTRACT: Different substances were evaluated and compared to an antibiotic, in terms of their effect on nitrogen - and amino acid digestibilities. Two digestibility trials and one performance trial were conducted. Trials one and two apparent nitrogen (AND)- and amino acid (AAD) digestibilities were determined from digesta collected at the terminal ileum (ileal digestibility method). In Trial 3 the substances were evaluated in terms of their potential to improve production performance. Broilers were fed a maizesoya based diet throughout the three trails. In the first trial, garlic and a commercial prebiotic (Bio-Mos®), were tested and compared in terms of AND and AAD, to an antibiotic (doxycyclin, Doxyvete-SOS). A starter and finisher diet were fed as either mash or pellets. The garlic was included at 8g/kg, 13g/kg and 18g/kg to the starter and finisher diets. Bio-Mos® was added at 1g/kg, 2g/kg and 3g/kg to the starter diet, and 0.5g/kg, 1g/kg and 1.5g/kg to the finisher diet. The doxycyclin was added at 0.3 g/kg. None of the treatments had any beneficial effects in terms of AND. Feeding a pellet seem to have some negative effects in terms of AND. In general most of the treatments did not show any improvement in AAD at any determination period (day 21, 28 or 35). At day 21 and day 35, the mash diet supplemented with 18g/kg garlic had a negative effect on AAD, when compared to the negative and positive control. It doesn’t seem that feeding either a mash or a pellet had an influence on the effects exerted by the different treatments. In the second trial the influence of Bio-Mos®, a blend of organic acids, probiotics and electrolytes (Acid-Pak 4-way®) and a medium-chain triglyceride (MCT) were evaluated and compared in terms of AAD and AND, to the effect of an antibiotic, doxycyclin. The starter and finisher diets were fed as a mash. Bio-Mos® was included at 1g/kg, 2g/kg, and 3g/kg in the starter diet, and at 0.5g/kg, 1g/kg, 1.5g/kg in the finisher diet, respectively. Acid-Pak 4-way® was included at 0.4g/kg, 1g/kg and 1.6g/kg for both the starter and finisher diets. Medium-chain triglycerides (MCT) were allocated at 3g/kg, 3.6g/kg, 4.2g/kg for the starter diet, and 2.1g/kg, 2.7g/kg and 3.4g/kg for the finisher diet. An antibiotic, doxycyclin, was included at 0.3 g/kg. With AND, no treatment had any significant effect for the entire experimental period. At day 21, the treatment supplemented with MCT (3.4g/kg) had the most significant beneficial effect on AAD, when compared to the negative- and positive controls, as it increased AAD for the majority of the amino acids. The treatment with Acid-Pak 4-way® (1g/kg) had the most significant negative effect on AAD when compared to the positive control. At day 28, the treatments with Bio-Mos® (0.5g/kg and 1.5g/kg) and Acid-Pak 4-way® (0.4g/kg) had the most significant beneficial effect on AAD when compared to the positive control. It increased AAD for more than half of the 17 amino acids evaluated. The treatment supplemented with MCT (2.7g/kg) has shown the most significant negative effect on AAD, when compared to the positive control. In the third trial the effect of Bio-Mos®, Acid-Pak 4-way® and MCT on production performance was evaluated, and compared to the effects of the presence or absence of doxycyclin. Body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were measured. The starter and finisher diets were fed as a mash. Bio-Mos®, MCT and Acid-Pak 4-way® were included at 3.0g/kg, 4.2g/kg and 1.6g/kg, respectively in the starter and finisher diets. Birds were weighed (per pen) on arrival and on days 7, 14, 21, 28, 35. Feed intake (FI) per pen was measured at days 7, 14, 21, 28 and 35, and mortality was recorded daily. In terms of BWG, Acid-Pak 4-way® had a higher BWG, when compared to the negative control, Bio-Mos® and MCT. It can be concluded that Bio-Mos®, Acid-Pak 4-way®, as well as MCT can be a possible alternatives to antibiotic supplementation. These three treatments did not necessary prove to be more effective than antibiotics, but are definitely competitive alternatives.
AFRIKAANSE OPSOMMING: Verskillende behandelings is geëvalueer en vergelyk met ‘n antimikrobiese produk, in terme van hul uitwerking op stikstof - en aminosuur verteerbaarhede. Twee verteringstudies en produksieprestasie studie is uitgevoer. In die eerste twee studies is die skynbare stikstof (AND)- en aminosuur (AAD) verteringskoöeffisiënte bepaal deur gebruik te maak van digesta wat by die terminale ileum ingesamel is (ileale verteringsmetode). In die derde studie is die produksie prestasie van braaikuikens op ‘n gebalanseerde metaboliseerbare energie (AME) rantsoen, soos beïnvloed deur die verskillende behandelings, geëvalueer. In die eerste studie is knoffel en ‘n kommersiële prebiotikum (Bio-Mos®) geëvalueer en met ‘n antibiotikum (doksisiklien, Doxyveto-SOS) in terme van AND en AAD vergelyk. Beginner- en afrondingsrantsoene is as ‘n meel of pille gevoer. Die knoffel is teen 8g/kg, 13g/kg en 18g/kg in die rantsoen ingesluit. Bio-Mos® is teen 1g/kg, 2g/kg en 3g/kg in die beginner rantsoen en teen 0.5g/kg, 1g/kg en 1.5g/kg in die afrondingsrantsoen, ingesluit. Die antibiotikum is teen 0.3g/kg in beide rantsoene ingesluit. Geen van die behandelings het enige positiewe invloed op AND gehad nie. Deur ‘n verpilde rantsoen te voer het sekere negatiewe invloed op AND gehad. Oor die algemeen het geen behandelings enige positiewe invloed op AAD gehad nie. Op dag 21 en 35 het die insluiting van knoffel teen 18g/kg in ’n meel rantsoen ’n negatiewe invloed op AAD gehad, wanneer dit met die negatiewe- en positiewe kontroles vergelyk is. Dit blyk nie dat om ‘n pil of meel te voer enige invloed op die invloede van die verskillende behandelings gehad het nie. In die tweede studie is Bio-Mos®, ‘n organiese suur (Acid-Pak 4-way®) en ‘n medium-ketting trigliseried (MCT) geëvalueer en met ‘n antbiotikum, doksisiklien (Doxyveto-SOS) in terme van AND en AAD, vergelyk. Beginner- en afrondingsrantsoene is gevoer as ‘n meel. Bio-Mos® is teen 1g/kg, 2g/kg, and 3g/kg in die beginner rantsoen en teen 0.5g/kg, 1g/kg, 1.5g/kg in die afrondingsrantsoen, ingesluit. Acid-Pak 4-way® is teen 0.4g/kg, 1g/kg en 1.6g/kg vir die beginner –en afrondingsrantsoene ingesluit. Die MCT is teen 3g/kg, 3.6g/kg, 4.2g/kg in die beginner rantsoen en teen 2.1g/kg, 2.7g/kg en 3.4g/kg in die afrondingsrantsoen ingesluit. Die antibiotikum is ingesluit teen 0.3g/kg. Geen behandelings het enige betekenisvolle invloed in terme van AND gehad nie. Op dag 21 het MCT (3.4g/kg), in vergelyking met die negatiewe- en positiewe kontrole, die grootste positiewe invloed op AAD gehad. Acid-Pak 4-way® (1g/kg) het, in vergelyking met die positiewe kontrole, ‘n positiewe invloed gehad op AAD. Op dag 28, het Bio-Mos® (0.5g/kg en 1.5g/kg) en Acid-Pak 4-way® (0.4g/kg) die grootste positiewe invloed op AAD gehad. Die behandeling met MCT (2.7g/kg) het die mees negatiewe invloed op AAD gehad. In die derde studie is die insluiting van Bio-Mos®, Acid-Pak 4-way® en MCT getoets om die invloed op braaikuiken produksie prestasie te evalueer, en te vergelyk met die invloed van die insluiting of afwesigheid van ‘n antibiotikum. Liggaamsmassa (BW), liggaamsmassa toename (BWG), voerinname (FI) en voeromsetverhouding (FCR) is gemeet. Beginner- en afrondings rantsoene is gevoer as ‘n meel. Bio-Mos®, MCT en Acid-Pak 4-way® is onderskeidelik teen 3.0g/kg, 4,2g/kg en 1.6g/kg in die rantsoen ingesluit. Die kuikens is met aankoms (per hok) geweeg, asook op dae 7, 14, 21, 28, 35. Voerinname per hok is gemeet op dae 7, 14, 21, 28 en 35. Mortaliteite is daagliks aangeteken. Die insluiting van Acid-Pak 4-way® het in vergelyking met die negatiewe kontrole, Bio-Mos® en MCT insluiting ‘n hoër BWG tot gevolg gehad. Die gevolgtrekking wat gemaak kan word is dat Bio-Mos®, Acid-Pak 4-way® en MCT gebruik kan word as ‘n moontlike alternatief vir antibiotika insluiting. Hierdie drie behandelings was nie noodwending meer effektief as die antibiotika nie, maar het wel bewys dat dit kompeterende alternatiewe is.

The objective of the study was to determine the effects of Aloe ferox inclusion in drinking water on growth performance, blood biochemistry, physico-chemical characteristics, fatty acid profile and oxidative stability of broiler meat. The importance of A. ferox as a medicinal plant and factors that influence its utilization by communal poultry farmers were also investigated by use of a questionnaire survey. The survey revealed that the majority of respondents (84.6%) faced health challenges in their chickens and many relied (96.2%) on A. ferox to treat diseases and control parasites. The study also revealed that the choice of medicine (traditional or conventional) was influenced (P<0.05) by level of education and income. In the second phase of the research, a total of 600 Ross 308 day-old broilers, were randomly put in 6 treatment groups with 4 replicates, each having 25 birds. Fresh aqueous A. ferox leaf juice (ALJ) was administered in drinking water at a dosage of 20ml/litre to T1, T2 and T3 from day one to day 35, day one to day 14 and day 15 to day 28, respectively. Birds in T4 and T5 (positive controls) were treated with terramycin at the recommended dosage of 14g/litre of drinking water from day one to day 6 and from day 15 to 20, respectively; and birds in T6 (negative control) received distilled water from day 1 to 35. Feed Intake (FI), average daily gain (ADG) and feed conversion ratio (FCR) were calculated for the 5 week trial. After slaughter, carcass characteristics particularly dressing percentage (DP) and relative organ weight (ROW) were calculated. Serum biochemistry was also determined. For meat quality, pH and color were recorded 45 minutes and 24 hours after slaughter from the breast muscle. Fatty acid profiling and oxidative stability were determined using meat samples from the breast and thigh muscles. The results for growth performance showed that thebirds which were given A. ferox for the first two weeks (T2) consumed significantly (P>0.05) more feed (189.4g) than those in the negative control (159.6g) at the beginning of the starter phase. Subsequently, their ADG recorded on day 7 (27.1g) and day 14 (43.1g) were significantly (P<0.05) higher than the negative control (22.8g and 36.2g, respectively). Significant treatment effects (P<0.05) for FCR were reported in the 4th week for the birds that received A. ferox throughout (T1: 3.5). Carcass characteristics were not significantly (P>0.05) affected by A. ferox inclusion in drinking water. The highest high density lipoprotein (HDL) values (2.78 mmol/L) were yielded in T2and T3 had the lowest values (0.61mmol/L) for low density lipoprotein (LDL). For physico-chemical properties, no significant effects (P>0.05) of treatment on pH, colour, cooking loss and tenderness were observed. However, the group treated with A.ferox throughout the production cycle, had the highest pH (6.2), lowest lightness (38.5), highest redness (4.1), highest tenderness (13.86N) and the lowest cooking loss (12.6%). Significant treatment effects (P<0.05) were observed on the composition of the PUFA eicosatrienoic acid (C20:3c8, 11, 14(n-6)) of the breast muscle which was significantly lower in the A. ferox treatment groups than the positive controls. For the thigh muscle, there were significant (P<0.05) treatment effects on composition of palmitoleic acid (C16:1c9) and g-linolenic acid (C18:3c6, 9, 12 (n-3)). No significant (P>0.05) effects were found on oxidative stability of both thigh and breast muscles. In conclusion, the wide use of A. ferox by communal chicken farmers showed its importance as a medicinal plant. Apart from it being an effective medicinal plant, A. ferox inclusion in drinking water results in improved FI, ADG, reduced in LDLC and better g-linolenic and palmitoleic acid composition in the meat.

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.

Thesis (MScAgric) -- University of Stellenbosch, 2000.
ENGLISH ABSTRACT: Lipids remain one of the most important nutrients required by broilers. The growing awareness that some Western societies have too high a dietary ratio of n-6/n-3 polyunsaturated fatty acids is of direct relevance to broiler nutrition and lipid metabolism. Meaningful quantities of n-3 polyunsaturates have been incorporated into major poultry tissues, so that the production of broiler meat with high n-3 polyunsaturates becomes advantageous for the broiler industry as they are perceived as having a 'healthier' lipid profile. Unfortunately, such broiler meat is rather susceptible to oxidative deterioration, and oxidation often determines shelf life of poultry meat products. The addition of a-tocopherol (vitamin E) to broiler diets is an effective means of improving the oxidative stability of broiler meat. Elevated a-tocopherol levels in broiler feeds increase tissue concentrations thereof resulting in improved stability of membranal structures which may be expected to increase the oxidative stability of broiler meat and meat products. Three investigations were done at Mariendahl Poultry Research Station in Stellenbosch. The broilers were kept in 1 x 0.4 x 0.5 m cages in a broiler rearing house. All the trials started with day-old chicks, except experiment 1 where 3-week old broilers were used. At the end of trials 2 and 3 the 6-week old broilers were slaughtered and the carcasses prepared for chemical analysis. Experiment 1: Metabolisabie energy of Canola acid oil and Famarol acid oil for broiler chickens. In trials with 21-day-old male broilers the true metabolisabie energy value, corrected for nitrogen retention (TMEn) was determined by the balance method for Canala acid oil (CAO) and Famarol acid oil (FAO). The trials were duplicated, each time using different samples of the two oils from the same source (experiment 1 and 2). Each of the two oils were blended in two ratios with a basal diet to form the test diets, viz. 100% Basal; 96% Basal: 4% Oil; 92% Basal: 8% Oil. In experiment 3, 50 % bran was added to the maize to form the basal diet. The balance trials lasted for 3 days after an adaptation period of 4 days. The TMEn values determined by regression for the broilers of CAO did not differ significantly (P>0.05) between experiments 1 and 2. However, the value for experiment 3 was significantly (P<0.05) higher than those for experiments 1 and 2. The TMEn values of FAO also did not differ significantly (P>0.05) between experiments 1 and 2, although the value for experiment 3 was significantly higher than that of experiment 1. The addition of 50 % bran to the basal diet in experiment 3 could have stimulated the digestive breakdown process and hence increase the secretion of digestive enzymes. This could lead to an increase in the utilisation of the test lipid and therefore an increase in the TMEn value. The TMEn values of CAO differed significantly (P<0.05) from those of FAO for all three the experiments (exp. 1:30.6 ± 0.399 MJ/kg for CAO vs. 25.9 ± 0.441 MJ/kg for FAO; expo 2: 31.0 ± 0.633 MJ/kg for CAO vs. 26.1 ± 0.668 MJ/kg for FAO: expo 3: 32.1 ± 0.867 MJ/kg for CAO vs. 27.1 MJ/kg for FAO).Experiment 2: of broilers. The dietary effects of various combinations of Canala acid oil (CAO, a high level of C18:3n-3 and MUFA) and Famarol Effects of various dietary n-6/n-3 fatty acid ratios on the perfonnance and body composition acid oil (FAO, a high level of 18:2n-6 and SFA) on tissue fatty acid composition were studied in broiler carcasses and abdominal fat pads. From day-old to six weeks, chicks were fed one of six diets containing 100% FAO, 80% FAO-20% CAO, 60% FAO-40% CAO, 40% FAO-60% CAO, 20% FAO-80% CAO, 100% CAO. There were no statistical differences (P>0.05) in average daily gain (1.71 ± 0.059 g) or feed conversion ratios (1.97 ± 0.051) among dietary groups. No statistical differences (P>0.05) were found in the chemical proximate composition of the carcasses for the moisture (66.20 ± 0.112 %), protein (17.63 ± 0.484 %), lipid (15.92 ± 1.507 %) and ash (0.95 ± 0.115 %) content among dietary groups. No statistical differences (P>0.05) were found in the chemical proximate composition of the abdominal fat pads for the moisture (28.77 ± 0.112 %), protein (3.03 ± 0.484 %), lipid (63.32 ± 9.789 %) and ash (0.45 ± 0.135 %) content among dietary groups. With the increase in dietary CAO levels, the percentages of C18:2n-6 and C20:4n-6 in the carcasses decreased respectively with 1.78 % from 20.88 % and 0.35 % from 1.05 %, whilst C18:3n-3 and longer chain n-3 fatty acids such as C20:5n-3 and C22:6n-3 increased respectively with 2.25 % from 1 %, 0.1 % from 0.1 % and 0.67 % from 0.2 %. The same tendency was seen in the abdominal fat pads where C18:2n-6 and C20:4n-6 decreased respectively with 1.55 % from 20.75 % and 0.98 % from 1.2 % with an increase in dietary CAO, whilst C18:3n-3, C20:5n-3 and C22:6n-3 increased respectively with 2.13 % from 1.15 %, 0.45 % from 0.03 % and 0.95 % from 0.05 %. The n-3/n-6 ratio in the carcasses and abdominal fat pads increased respectively with 0.16 % from 0.06 % and 0.19 % from 0.06 % with an increase in dietary CAO. These results clearly indicate that dietary CAO enriched with a-linolenic acid lower saturated fatty acids respectively in broiler carcasses and abdominal fat pads with 4.88 % from 31.6 % and 10.63% from 31.1 %, whilst increasing monounsaturated fatty acids with 3.87 % from 44.95 % and 7.25 % from 46.7 % respectively and polyunsaturated fatty acids with 1.02 % from 23.45 % and 2.38 % from 23.2 % respectively. Experiment 3: Effect of dietary vitamin E on the performance of broilers and oxidative stability, colour, microbiological stability, fatty acid composition and pH of broiler meat during refrigerated and frozen storage. Experiment 1 was carried out with 220 one-day-old broiler chicks to evaluate the effect of eleven concentrations of vitamin E (0, 20, 40, 60, 80, 100, 120, 140, 160, 180 and 200 mg a-tocopheryl acetate 1 kg diet) on their production performance and the oxidative stability of their frozen broiler carcasses. The diets with vitamin E levels 0 to 100 mg were fed from day-old to 42 days of age while the diets with vitamin E levels 120 to 200 mg were fed from 21 to 42 days of age. The oxidative stability, evaluated by thiobarbituric acid reactive substances (TBARS) values, was determined after 30, 90, 120 and 150 days of storage at -20°C. There were no statistical differences (P>0.05) in average daily gain (1.85 ± 0.111 g) or feed conversion ratios (2.29 ± 0.397) among dietary groups. TBARS values increased significantly (P<0.05) with increasing time of storage (basal diet: day 30 = 1.71 ± 0.51; day 150 = 4.89 ± 0.51), but decreased significantly (P<0.05) with increasing vitamin E levels (day 150: basal = 4.89 ± 0.51; 100 mg / kg = 1.09 ± 0.27). Experiment 2 was carried out with day-old broiler chicks to evaluate the effect of five concentrations of vitamin E (0, 40, 80, 120 and 160 mg atocopheryl acetate / diet) on their performance and the oxidative stability of their refrigerated carcasses. The experimental diets were fed from day-old to 42 days of age. The oxidative stability, evaluated by TBARS values, colour deterioration and microbiological stability were determined after 0, 4, 8, 10 and 12 days of storage at 4°C. Fatty acid analysis was done on the samples of days 0 and 12. There were no statistical differences (P>0.05) in average daily gain (1.88 ± 0.117 g) or feed conversion ratios (2.37 ± 0.467) among dietary groups. TBARS values increased significantly (P<0.05) with increasing time of storage, but decreased significantly (P<0.05) with increasing vitamin E levels. There were no statistical differences (P>0.05) in colour measurements for L* (44.97 ± 0.662), a* (5.23 ± 0.315) or b* (12.76 ± 0.321) values between treatments. Microbiological counts increased significantly (P<0.05) over time with vitamin E concentration showing no effect. There were no statistical differences (P>0.05) for any of the fatty acid groups measured (SFA: Day 0 = 26.1 ± 1.13%, Day 12 = 26.1 ± 1.17%; MUFA: Day 0 = 41.4 ± 1.46%, Day 12 = 40.2 ± 2.28%; PUFA: Day 0 = 32.4 ± 1.95%, Day 12 = 33.8 ± 2.52%) among dietary groups. Similarly, none of the fatty acids showed statistical significant (P>0.05) concentration changes over time. There were no statistical differences (P>0.05) in pH (6.01 ± 0.206) among dietary groups.
AFRIKAANSE OPSOMMING: Lipiede is steeds een van die mees belangrike voedingstowwe wat deur braakuikens benodig word. Die groeiende bewuswording dat sekere Westerse gemeenskappe 'n te hoë verhouding van n-6/n-3 poli-onversadigde vetsure in hul dieet het, is direk relevant vir braaikuikenvoeding en lipiedmetabolisme. Betekenisvolle hoeveelhede n-3 polionversadigde vetsure is geïnkorporeer in die belangrikste hoendersnitte, met die gevolg dat die produksie van braaikuikenvleis met hoë n-3 poli-onversadigde vetsure voordelig is vir die braaikuikenindustrie en geag word 'n meer "gesonde" beeld te hê. Ongelukkig is sodanige braaikuikenvleis redelik vatbaar vir oksidatiewe bederf, en oksidasie bepaal dikwels die rakleeftyd van hoendervleisprodukte. Die byvoeging van a-tokoferol (vitamine E) by braaikuikendiëte is 'n effektiewe manier om die oksidatiewe stabiliteit van braaikuikenvleis te verbeter. Verhoogde a-tokoferol vlakke in braakuikenvoere verhoog die weefselkonsentrasie wat verhoogde stabiliteit van die membraanstrukture en derhalwe moontlike verhoogde oksidatiewe stabiliteit van braakuikenvleis en -produkte tot gevolg het. Drie ondersoeke is onderneem by Mariendahl Pluimvee Navorsingstasie te Stellenbosch. Die braakuikens is aangehou in 1 x 0.4 x 0.5m hokke in braaikuikenhuise. In al die proewe is dagoud kuikens gebruik, behalwe eksperiment 1 waar drieweek oue kuikens gebruik is. Aan die einde van proewe 2 en 3 is die ses-week oue braaikuikens geslag en die karkasse voorberei vir analise. Eksperiment 1: braaikuikens. Die ware metaboliseerbare energie waarde van Canola voergraadolie (CAO) en Famarol voergraadolie (FAO), Metaboliseerbare energie van Canola voergraadolie en Famarol voergraadolie vir gekorregeer vir stikstof retensie (WMEn), is by wyse van proewe op 21 dae oue braaikuikenhaantjies bepaal deur van die balansrnetode gebruik te maak. Die proewe is tweemaal herhaal vir verhoogde akkuraatheid, met die gebruik van verskillende monsters van die twee olies vanaf dieselfde bron. Die olies is in twee verhoudings met 'n basale diëet gemeng om die proef dieet te vorm, nl. 100% Basaal; 96% Basaal: 4% Olie en 92% Basaal: 8% Olie. Die balans proewe het 3 dae geduur na afloop van 'n aanpassingsperiode van 4 dae. Die WMEn waardes van CAO, bepaal deur middel van regressie analise, het nie betekenisvol verskil (P>0.05) tussen eksperimente 1 en 2 nie. Die waarde van eksperiment 3 was betekenisvol hoër (P<0.05) as die van die eerste twee eksperimente. Die WMEn waardes van FAO het ook nie betekenisvol verskil (P>0.05) tussen eksperimente 1 en 2 nie, maar die waarde vir eksperiment 3 was betekenisvol hoër as dié van eksperiment 1. Die WMEn waardes van COA het betekenisvol verskil (P< 0.05) van dié van FAO vir al die eksperimente (exp. 1: 30.6 ± 0.399 MJ/kg vir CAO vs. 25.9 ± 0.441 MJ/kg vir FAO; expo 2: 31.0 ± 0.633 MJ/kg vir CAO vs. 26.1 ± 0.668 MJ/kg vir FAO: expo 3: 32.1 ± 0.867 MJ/kg vir CAO vs. 27.1 MJ/kg vir FAO). Eksperiment 2: Die invloed van verskeie rantsoen n-6/n3 vetsuurverhoudings op die produksie en liggaamsamestelling van braaikuikens. Die rantsoeneffek van verskeie kombinasies Canola voergraadolie (CAO, 'n hoë vlak van C18:3n-3 en monoonversadigde vetsure) en Famarol voergraadolie (FAO, 'n hoë vlak van 18:2n-6 en versadigde vetsure) op die weefselvetsuursamestelling is bestudeer in braaikuikenkarkasse en abdominale vetneerlegging. Die kuikens is van dagoud to op ses-weke ouderdom een van ses diëte gevoer met die volgende samestellings: 100% FAO, 80% FAO-20% CAO, 60% FAO - 40%CAO, 40% FAO - 60% CAO, 20% FAO - 80% CAO, 100% CAO. Daar was geen statistiese verskil tussen die rantsoengroepe (P>0.05) in die gemiddelde daaglikse toename (1.71 ± 0.059 g) of die voeromsetverhoudings (1.97 ± 0.051) nie. Geen statistiese verskil (P>0.05) is gevind in die chemiese samestelling van die karkasse vir vog (66.20 ± 0.112 %), proteïn (17.63 ± 0.484 %), lipied (15.92 ± 1.507 %) en as (0.95 ± 0.115 %) inhoud tussen die rantsoen groepe nie. Geen statistiese verskille (P>0.05) is gevind in die chemiese samestelling van die abdominale vetneerlegging vir vog (28.77 ± 0.112 %), proteien (3.03 ± 0.484 %), lipied (63.32 ± 9.789 %) en as (0.45 ± 0.135 %) inhoud onder die rantsoengroepe nie. Met die verhoging in die rantsoen CAO vlakke het die persentasie van C18:2n-6 en C20:4n-6 in die karkasse verminder met 1.78 % en 0.35 % respektiewelik, terwyl C18:3n-3 en langer ketting n-3 vetsure soos C20:5n-3 en C22:6n-3 respektiewelik met 2.25 %, 0.1 % en 0.67 % verhoog het. Dieselfde tendens is opgemerk in die abdominale vetneerlegging waar C18:2n-6 en C20:4n-6 afgeneem het met 1.55 % en 0.98 % respektiewelik met die verhoging van rantsoen CAO, terwyl C18:3n-3, C20:5n-3 en C22:6n-3 verhoog het met 2.13 %, 0.45 % en 0.95 % respektiewelik. Die n- 3/n-6 verhouding in die karkasse en abdominale vetneerlegging het verhoog met 0.16 % en 0.19 % respektiewelik met die verhoging van die rantsoen CAO. Die resultate toon onomwonde aan dat rantsoen CAO verryk met c-Iinoletensuur, verlaag versadigde vetsure in braaikuikenkarkasse en -adbdominale vetneerleggings met 4.88 % en 10.63% respektiewelik, terwyl die mono-onversadigde vetsure met 3.87 % en 7.25 % respektiewelik verhoog word en polionversadigde vetsure met 1.02 % en 2.38 % respektiewelik verhoog word. Eksperiment 3: Die invloed van vitamine E op die produksie van braaikuikens en die oksidatiewe stabiliteit, kleur, mikrobiologiese stabilitiet, vetsuursamestelling en pH van braaikuikenvleis gedurende verkoelde en bevrore berging. Eksperiment 1 is uitgevoer met 220 dagoud braaikuikens ten einde die effek van elf konsentrasies van vitamine E (0, 20, 40, 60, 80, 100, 120, 140, 160, 180 en 200 mg a-tokoferyl acetaat / kg voer) op hul produksieprestasie en die oksidatiewe stabiliteit van hul gevriesde braakuikenkarkasse te evalueer. Die diëte met vitamine E vlakke 0 tot 100 mg is vanaf dagoud tot 42-dae-ouderdom gevoer, terwyl die diëte met vitamine E vlakke van 120 tot 200mg gevoer is vanaf 21 tot 42- dae-ouderdom. Die oksidatiewe stabiliteit, soos geëvalueer deur tiobarbituriese suur reaktiewe stowwe (TBARS) waardes, is bepaal na 30, 90, 120 en 150 dae van berging teen -20°C. Daar was geen statistiese verskille (P>0.05) in die gemiddelde daaglikse toename (1.85 ± 0.111 g) of voeromsetverhoudings (2.29 ± 0.397) tussen die rantsoengroepe nie. TBARS waardes het betekenisvol toegeneem (P<0.05) met die verhoging in bergingsperiode, maar het betekenisvol afgeneem (P<0.05) met verhoogde vitamine E vlakke. Eksperiment 2 is uitgevoer met dagoud braaikuikens ten einde die effek van vyf konsentrasies van vitamine E (0, 40, 80, 120 and 160 mg a-tokoferyl acetaat / kg voer) op hul prestasie en die oksidatiewe stabiliteit van hul verkoelde karkasse te evalueer. Die eksperimentele diëte is gevoer vanaf dagoud tot 42- dae-ouderdom. Die oksidatiewe stabiliteit, geëvalueer deur middel van TBARS waardes, kleur afname en mikrobiologiese stabiliteit is bepaal na 0, 4, 8, 10 en 12 dae van berging teen 4°C. Vetsuuranalises is gedoen op die monsters van dae 0 en 12. Daar was geen statistiese verskille (P>0.05) in die gemiddelde daaglikse toename (1.88 ± 0.117 g) of voeromsetverhoudings (2.37 ± 0.467) tussen die rantsoengroepe nie. TBARS waardes het betekenisvol verhoog (P<0.05) met die verlengde bergingsperiode, maar het betekenisvol afgeneem (P<0.05) met verhoogde viatmine E vlakke. Daar was geen statistiese verskille (P>0.05) in kleur metings vir L* (44.97 ± 0.662), a* (5.23 ± 0.315) of b* (12.76 ± 0.321) waardes tussen behandelings nie. Mikrobiologiese tellings het betekenisvol verhoog (P<0.05) oor tyd met die vitamine E konsentrasie wat geen effek getoon het nie. Daar was geen statisties betekenisvolle verskille (P>0.05) vir enige van die vetsuurgroepe tussen die behandelings nie. Soortgelyks het geen van die vetsure statisties betekenisvolle (P>0.05) konsentrasieveranderings oor tyd aangetoon nie. Daar was geen statistiese verskil (P>0.05) in die pH (6.01 ± 0.206) tussen die rantsoengroepe nie.

High feed costs are part of any broiler rearing enterprise and continuous effort is required to help overcome this problem. The use of a feed expander may be beneficial in improving bird performance and thus increasing the profitability of broiler meat production. Four experiments were conducted to evaluate the performance of birds fed expanded feed in relation to the performance of birds fed non-expanded feed. The effect of feeding birds expanded feed was also tested under heat stress conditions. In this experiment, a significant improvement in cumulative feed conversion ratio (CFCR) was observed for birds fed expanded feed (Chapter 3). Pellet size influenced bird performance as birds fed a 3.2 mm non-expanded feed had a better cumulative FCR than the non-expanded 4.5 mm pellets, and this CFCR did not differ significantly from that in birds fed 3.2 mm expanded pellets (Chapter 4). There is, however, an improvement in the cumulative FCR to two weeks of age in birds fed expanded feed, over that in birds fed non-expanded feed, indicating that expanding of feed improves nutrient availability to the young broiler with a partially developed digestive tract. The effects of expanding feed on the body weight of birds were not consistent between experiments. This might be attributed to expanding temperature, as the feed in Chapters 3 and 4 was expanded at 90°C and not at higher temperatures as in the other chapters. Expanding feed at 90°C may not allow proper starch gelatinisation and alteration of nutrient availability. Expanded feed had better pellet durability than non-expanded feed and there were no significant negative effects on vitamin recovery, enzyme stability and nutrients when feed was expanded at temperatures between 95 and 1 05°C. Pellet quality increased with an increase in expanding temperature. Expanding of broiler feed led to a significant improvement in lipid digestibility (Chapter 6). Expanding of feed at 105°C is recommended as feed expanded at this temperatures tend to have significantly higher AMEn values for broilers than non-expanded feed.
Dissertation (MSc(Agric))--University of Pretoria, 2012.
Animal and Wildlife Sciences
unrestricted

Thesis (M.Sc. (Animal Production)) --University of Limpopo, 2019
Two experiments were conducted to determine the effect of dietary threonine level on production performance and carcass characteristics of Ross 308 broiler chickens. In each experiment the diets were isocaloric and isonitrogenous but with different dietary threonine levels.The first part of the study determined the effect of dietary threonine level on feed intake, growth rate, mortality and carcass characteristics of Ross 308 broiler chickens aged between Day 1-21. A total of 150 unsexed day-old chicks were used in a complete randomized design having 5 treatments (6.4, 7.5, 8, 8.5 and 9g of threonine/kg DM feed), replicated three times and having ten chickens per replicate. The second part of the study determined the effect of dietary threonine level on feed intake, digestibility, growth rate, mortality and carcass characteristics of male Ross 308 broiler chickens aged between Day 22-42. Seventy-five male chickens were used in a complete randomized design having 5 treatments (6.4, 7.5, 8, 8.5 and 9g of threonine/kg DM feed), replicated three times and having five chickens per replicate. A quadratic regression model was used to determine the optimal productivity of the chickens while a General Linear Model (GLM) procedures for the statistical analysis of variance was used to detect dietary treatment effects. Where there were significant differences (P<0.05), Turkey’s honestly significant difference test (HSD) was used for mean separation. The chickens were slaughtered at the ages of 21 and 42 days for Experiments 1 and 2, respectively, following ethical standards as recommended by the University of Limpopo Animal Research Ethics Committee (AREC/12/2017: PG). Two chickens per replicate for both studies were slaughtered for the determination of carcass characteristics (carcass and organ weights, gut organ digesta pH and gastro-intestinal length measurements). Dietary threonine levels used in this experiment affected (P<0.05) feed intake, growth rate, live weight, metabolisable energy (ME) intake, nitrogen retention, feed conversion ratio and gut organ weights and lengths of unsexed Ross 308 broiler chickens aged 21 days. Dietary threonine level did not affect (P>0.05) diet digestibility. Feed conversion ratio, pH of the proventriculus digesta, gut intestine length and caecum length of unsexed broiler chickens were optimized at different dietary threonine levels of 9.6, 8.5, 6.6 and 8.4 g/kg DM, respectively. Dietary threonine levels had an effect (P<0.05) on feed intake, diet digestibility, metabolizable energy, live weight, proventriculus pH values, GIT length, gut organ and carcass organ weights of male Ross 308 broiler chickens between 22 to 42 days of age. Proventriculus and large intestine weights were optimized at different dietary threonine levels of 7.5 and 9.1 g/kg DM feed, respectively. Dietary threonine level did not affect (P>0.05) growth rate, feed conversion ratio of male Ross 308 broiler chickens between 22 to 42 days of age. It is concluded that dietary threonine levels used in this study affected production performance of younger broilers (Day 1-21) more than that of older birds (Day 22-42). However, production variables were optimized at different dietary threonine levels. This has implication on diet formulation for the chickens and no linear response could be established
National Research Foundation (NRF), and the Department of Agriculture, Forestry and Fisheries (DAFF)

Rice bran arises as a by-product from rice milling industry. The anti-nutritional substances such as phytate, non-starch polysaccharides, protease inhibitor and lectin limit the nutritional value of this by-product. This research was directed toward the nutritional improvement of defatted rice bran (DRB) using feed enzymes to degrade these anti-nutritional factors. Three growth experiments and two tube feeding experiments were carried out to investigate the effect of phytase, carbohydrase and protease enzymes (supplied by Finnfeeds International) on broiler performance, mineral retention, nutrient digestibility, digesta viscosity and bone characteristics of chicken fed defatted rice bran based broiler diets. Enzyme supplementation of diets was conducted to assess the effects of individual and a cocktail of enzymes and/or lactobacillus culture. The data showed that inclusion of DRB at more than 150 g/kg without additional inorganic phosphate reduced feed intake, growth, bone mineralisation and produced the symptoms of rickets in broiler chickens. Experimental phytase successfully released phosphorus from DRB which counteracted the symptoms of a phosphorus deficient rickets-producing diet and improved feed intake, growth and bone mineralisation. Data presented in this study indicate that inclusion of DRB in broiler diets did not produce viscous digesta in the gut and carbohydrase supplementation did not improve bird performance, nutrient digestibility and mineral retention. The digesta viscosity was not decreased by carbohydrase; therefore, the non-starch polysaccharide (NSP) content of DRB did not play an important role in production of viscous digesta. Supplementation of DRB based broiler diets with protease improved dry matter (DM) and protein digestibility and P retention; therefore, the improvement in feed conversion ratio (FCR) was a result of better utilisation of nutrients. The data showed that there is a potential to decrease the phytate and lectin content of DRB broiler based diets by supplementing diets with phytase and protease.

The South African poultry industry is a large part of the agricultural industry and a very important contributor to the Agriculture’s Gross Domestic Product. Furthermore, this industry is expanding and very good growth is predicted for the next decade. This growth will take place in the formal as well as the informal segments of the industry. The informal segment holds a lot of potential for suppliers to supply in their growing needs. Due to the fact that broiler feed is seen as a large contributor to the total cost of broiler production, it is considered very important factor. If feed suppliers want to focus on the informal market, they need to understand the differences between commercial farmers and small–scale farmers and specifically the different needs of small–scale farmers. To develop a strategy to utilize the opportunities in the informal market, it is necessary to understand all the factors that influence the purchase behaviour of these farmers. A model of stimulus response is used to define the factors that may influence purchase behaviour. The factors that seemed important from the literature study are market and other stimuli. The market stimuli consist of product, price, promotion and place. The product aspect could further be divided into quality aspects, brand equity, and additional services that accompany the product. Other stimuli that could influence purchase behaviour are economic conditions, special event, climatic condition and the influence of culture. Data was collected by means of a questionnaire. Descriptive statistics and factor analysis were used on the data to determine which factors influence the small–scale farmers’ purchase behaviour. While the Kaiser Meyer Olkin measure, Bartlett’s test of shericity and Cronbach Apha were used to determine if the data is suitable to do a factor analysis on. Factor analysis was done to determine which factors are the most important. The seven significant factors that influence the purchase behaviour of small–scale farmers are: * Value for money and opportunity. * Perceived brand value. * Customer support and service. * Consensus on available quality. * Brand loyalty. * Feed price at the reseller. * Bag size. More research on this topic in a larger geographical area is required.
Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.

The main objective of the study was to determine how phase feeding manipulation affects growth performance, feed cost, carcass characteristics and quality of meat from broiler chickens. A total of 180 day old un-sexed broiler chicks (Cobb 500) were separated into 3 dietary treatments of 60 birds per treatment and each treatment was replicated 3 times with 20 birds per replicate. The dietary treatments were as follows: T1 (starter 1-7 days; grower 8-21 days; finisher 22-35 days), T2 (starter 1-14 days; grower 15-21 days, finisher 22-35 days) and T3 (starter 1-14 days; grower 15-28 days; finisher 29-35 days). Feed intake and body weight gains were recorded weekly in kilograms. Average daily gain and feed conversion ratio were computed weekly. At day 35, the chickens were slaughtered and 12 representative breast muscles from each treatment were used for the determination of muscle pH (pH1, pH24 and pH48) and colour coordinates (Lightness – L*, redness – a* and yellowness – b*) in triplicate at 1 hour, 24 hours and 48 hours post-mortem.Feed intake (FI), feed conversion ratio (FCR), average daily gain (ADG) and average body weight at slaughter (ABW) were not significant (P>0.05) amongst the treatments. The most cost efficient feed (which accumulated the cheapest cost feed per kg were) T1 (R11.32) and T3 (R11.32) although there was a slight difference in the gross profit of these treatments T1 (R45.71) and T3 (R44.48). Carcass characteristics were the same (P > 0.05) across the treatments except for the wing, thigh, drumstick and the breast (P < 0.05). T2 had the highest wing weight (166.63±8.60), T1 (113.03±8.60) and the lowest in T3 (74.46±8.60). The thigh weight were greater (P<0.05) in T2 (185.69±4.34); T1 (185.54±4.34) compared to T3 (166.97±4.34) which was lower. Treatments 1 (204.17±6.57), T2 (197±6.57) had heavier (P<0.05) breast weights than T3 (186.06±6.57). Dietary treatments had no significant effect (P > 0.05) on pH of the breast meat. No differences were observed in colour during the 1 hour period after slaughter. At 24 hours after slaughter, the L* values were different (P < 0.05) in T1 and T2 (44.3 ± 0.37; 43.7 ± 0.37), respectively, T1 and T3 were the same. The a*-values were different (P < 0.05) at 48 hours after slaughter for T1 and T3 (4.5 ± 0.27; 3.4 ± 0.27), T2 was the same as T1. It was therefore, concluded that since manipulation of starter phase did not have adverse effects on growth performance, gross profit, slight statistical difference in meat quality attributes and carcass characteristics. Therefore, the manipulation of starter diet has the potential to be used in broiler production.

Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2005.
Broiler diets are supplemented with feed phosphates to ensure that adequate available phosphorus is provided in the diet to meet the bird’s requirements. These feed phosphates make a considerable contribution to the total available phosphorus in the diet and small differences in their availability may have significant effects on whether the bird’s requirements are met or not. The variation in availability of phosphorus between feed phosphates belonging to different classes and between feed phosphates of the same generic class is well documented.

Master of Science
Department of Animal Sciences and Industry
R. Scott Beyer
Over the decades much has been discovered about the appropriate lighting management strategies for raising commercial meat-type poultry. Our knowledge of light preference, wavelength, intensity, intermittent lighting, and avian spectral sensitivity continues to improve our management strategies. In this work, a total of 5 experiments were conducted. The first 2 experiments investigated the effects of Light emitting diodes (LED) lights on growth performance of broiler chicks. Broiler chicks were raised under LED lights at different intensities: 5, 10, 15, 20, and 25 lux. A significant linear relationship (P < 0.05) was found in experiment 1 between body weight gain and light intensity. In experiment 2, a linear trend was noticed between body weight gain and light intensity. As the light intensity increased, chick weight increased. Feed: gain ratios were not affected by light intensity. The third experiment also examined growth performance using LED lighting as well as the effects of feed form and different lighting intensities upon behavior. The broilers fed a pelleted diet had significantly better performance than those fed crumbles. Under more intense light it was discovered that broilers spend significantly more time (P< .05) consuming feed compared to dim light. The fourth experiment focused on broiler preference for light color, and feed form during feeding. The broilers were offered either pelleted or crumbled feed and served under 4 different light colors: red, white, blue, and green. It was found that broilers statistically preferred pelleted feed, and white lighting, with red being the 2nd color choice of preference while green and blue were statistically not chosen. The fifth experiment focused on chick preference for feed color, when under different light color. One day old chicks were offered dyed feed: red, yellow, blue, green or light brown iv (control) under 5 different colors of light: red, yellow, blue, green, and white. It was found that chicks significantly preferred red dyed feed, especially under blue light. In conclusion, it was found that LED lights can have positive effects on broiler performance. Broilers show a preference for white lighting and pelleted feed. Young chicks show a preference for red dyed feed.

Doctor of Philosophy
Department of Animal Sciences and Industry
R. Scott Beyer
Broiler chicken feed is processed. Cereal grains are ground to reduce particle size and the feed usually is pelleted. When pelleted, broiler diets are steam conditioned and forced through a die causing varying levels of starch gelatinization. Cereal grain particle size and starch gelatinization can be controlled during feed manufacturing. Earlier research has shown that starch gelatinization negatively affects growth performance of 0 to 21 d of age. An experiment was conducted to determine the effects of corn particle size and starch gelatinization on growth performance, dressing percentage, and gizzard size when fed to 22 to 42 d of age broilers. Increasing particle size from 470 to 1240 μm increased body weight gain, dressing percentage, and relative gizzard size. Starch gelatinization increased relative gizzard size. No interaction effects were detected. To expand on previous experiments, a trial was conducted to investigate the effect of starch gelatinization on broiler chick gastrointestinal pH, glucose absorption, and glucoregulation. Starch gelatinization level affected jejunum pH, with a higher pH reported at 20% starch gelatinization. Increases in starch gelatinization decreased blood glucose and increased glucagon level. Highest measured glucagon level was reported in broiler chicks fed the diet with 20% starch gelatinization level diet after 6 hours of starvation. A third experiment was conducted to determine the effect of starch gelatinization on metabolizable energy and amino acid digestibility. Increasing starch gelatinization from 0 to 100% increased true metabolizable energy and fecal output in roosters. No effect was found on apparent metabolizable energy or amino acid digestibility, with an increase in starch gelatinization from 0 to 20%. Increasing particle size from 470 to 1240 μm had a positive effect on 22 to 42 d growth performance. A starch gelatinization level of 20% or lower had no effect on metabolizable energy or amino acid digestion. Older broilers with larger gastrointestinal tracts are unaffected by 20% gelatinized starch; whereas, 20% gelatinized starch reduced blood glucose and increased glucagon levels of young broilers. Lower blood glucose and increased glucagon are indicative of lower glucose storage, and could cause reduced young broiler growth performance when fed diets with gelatinized starch.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior
A pesquisa foi desenvolvida com o objetivo de avaliar os efeitos da adiÃÃo do anacardato de cÃlcio (ACC), como fonte de Ãcido anacÃrdico na raÃÃo de frangos de corte sobre o desempenho, as caracterÃsticas de carcaÃa, qualidade e a estabilidade lipÃdica da carne, parÃmetros sanguÃneos, atividade enzimÃtica e peroxidaÃÃo lipÃdica do fÃgado e no crescimento, composiÃÃo e qualidade dos ossos. Para isso, 840 pintos machos de um dia da linhagem Ag Ross 308 foram distribuÃdos ao acaso em seis tratamentos, com sete repetiÃÃes de vinte aves. Os tratamentos consistiram em: raÃÃo sem promotor de crescimento (PC); raÃÃo com PC e, os demais, raÃÃes sem o PC e adiÃÃo de ACC nos nÃveis de 0,25; 0,50; 0,75 e 1%. A adiÃÃo de ACC na raÃÃo nÃo influenciou nos parÃmetros bioquÃmicos do sangue (Ãcido Ãrico, creatinina, alanina aminotransferase, aspartato aminotransferase, colesterol total, HDL, LDL e triglicerÃdeos), na atividade enzimÃtica (superÃxido dismutase, grupos sulfidrÃlicos nÃo-protÃicos) e peroxidaÃÃo dos lipÃdeos do fÃgado, no crescimento e qualidade Ãssea (peso, comprimento, diÃmetro, Ãndice de Seedor, resistÃncia, deformidade, matÃria seca e matÃria mineral), nas caracterÃsticas de carcaÃa (% de carcaÃa, peito e coxa+sobrecoxa) e na qualidade da carne ( L*, a*, b*, pH, perda de Ãgua por cocÃÃo e capacidade de retenÃÃo de Ãgua). No entanto, a adiÃÃo a partir de 0,75% de ACC reduziu o ganho de peso e prejudicou a conversÃo alimentar dos frangos atà 21 dias de idade, porÃm, a adiÃÃo de atà 1% nÃo afetou o desempenho quando se considerou o perÃodo total de criaÃÃo (1 a 42 dias de idade). Para os valores de TBARS da carne, os nÃveis de 0,75% e 1% proporcionaram os menores valores, enquanto, o tratamento sem promotor de crescimento proporcionou maior valor. O ACC pode ser adicionado na raÃÃo dos frangos de corte atà o nÃvel de 1%, sem que ocorram alteraÃÃes nos parÃmetros sanguÃneos, enzimÃticos do fÃgado, no desempenho ao final do perÃodo de criaÃÃo (42 dias de idade), nas caracterÃsticas de carcaÃa e no crescimento, composiÃÃo e qualidade dos ossos. Contudo, a qualidade da carne pode melhorar com a reduÃÃo da oxidaÃÃo lipÃdica a partir de 0,75%.
The research aims to evaluate the effects of adding calcium anacardic (CAC) as a source of anacardic acid in the feed of broiler about the performance, carcass characteristics, quality and lipid stability meat, blood parameters, enzyme activity and lipid peroxidation liver and growth, composition and quality of the bones. For this, 840 male chicks with a day Ross 308 line were randomly assigned to six treatments, with seven replicates of twenty birds. The treatments consisted of: diet without growth promoter (PC); diet with PC and the others without PC and adding CAC levels of 0.25; 0.50; 0.75 to 1%. The addition of CAC in the feed didnât affect the biochemical blood parameters (uric acid, creatinine, alanine aminotransferase, aspartate aminotransferase, total cholesterol, HDL, LDL and triglycerides) in the enzyme activity (superoxide dismutase, non-protein sulfhydryl groups) and peroxidation of liver lipids, growth and bone quality (weight, length, diameter, Seedor index, strength, deformity, dry matter and mineral matter), in the carcass characteristics (% of carcass, breast and thigh + drumstick) and quality meat (L *, a *, b *, pH, loss of water by cooking and water holding capacity). However, the addition of from 0.75% CAC reduced weight gain and feed conversion detracted from the chickens up to 21 days old, however, the addition of up to 1 % did not affect performance when considering the total period (1 to 42 days old). For TBARS values for beef, the levels of 0.75% to 1% have provided the lowest values while treatment without growth promoter yielded higher value. The CAC can be added in the feed of broilers to the level of 1 %, no changes occur in the blood parameters and enzyme of the liver, the performance at the end of the growing period (42 days old), carcass characteristics and growth, composition and quality of the bones. However, the quality of the meat can improve with reduced lipid oxidation from 0,75. The CAC can be added in the feed of broiler until the level of 1%, without change the blood parameters, enzymatic liver, the performance at the end of the growing period (42 days old), carcass characteristics and growth, composition and quality of the bones. However, the quality of the flesh can be improved by reducing lipid oxidation as 0.75%.

In the broiler industry, chicks are often deprived of feed and water up to 48 h posthatch. This delayed access to feed (DAF) has been found to inhibit small intestinal development, compromising growth of the chick. To further understand the impact of DAF on small intestines at the molecular level, many developmental genes that regulate intestinal development were investigated. The objective of this study was to determine the effect of DAF on early posthatch broiler small intestinal morphology, which includes villus height (VH) and crypt depth (CD), and to quantify changes in regulatory genes, such as Olfactomedin 4 (Olfm4), Marker of Ki-67 (Ki-67), Peptide Transporter 1 (PepT1), and Mucin 2 (Muc2), in response to DAF. The Olfm4 mRNA can clearly identify stem cells in the intestinal crypt, which allows VH and CD to be measured, while Ki-67 marks the proliferating cells. The peptide transporter PepT1 is located on intestinal epithelial cells and plays a critical role in transporting di- and tripeptides. Muc2, which is secreted from goblet cells, forms mucus that lines the intestinal epithelial cells acting as a layer of protective coating. Cobb 500 chicks, hatching within a 12 h window, were randomly allocated into three experimental groups: control with no feed delay (ND), 24 h feed delay (D24), and 36 h feed delay (D36). Quantification of Olfm4, Ki-67, PepT1, and Muc2 mRNA abundance were investigated by quantitative PCR, in duodenum, jejunum, and ileum at 0 h, 24 h, 36 h, 72 h, 120 h, and 168 h posthatch. Additionally, localization of cells expressing each gene was visualized using in-situ hybridization at all listed times except 168 h posthatch. Statistical analysis was performed using JMP Pro 14, and significant differences between treatments within a collection day were determined by t-test and one-way ANOVA (P < 0.05). In the ND group, duodenal CD at 0 h was greatest compared to all other time points. With DAF, the duodenal VH of D36 chicks was lower at 36 h (P < 0.001) and 72 h (P = 0.002) compared to ND chicks. In the jejunum and ileum, the VH of D36 chicks was lower at 120 h (P = 0.005) and 72 h (P = 0.03), respectively, compared to ND chicks. In contrast, the VH of D24 chicks at 24 h was greater than ND (P = 0.004) in the jejunum. There was no difference between treatments by 168 h in all intestinal segments. The CD was also lower in DAF groups compared to ND but only in the jejunum and ileum. In contrast, duodenal CD was greater in D24 chicks at 24 h (P = 0.039) and in D36 chicks at 36 h (P < 0.0001) compared to ND chicks, but the difference was no longer significant by 72 h. The VH/CD ratio was lower in all three segments, except the ileum displayed a greater VH/CD ratio in D24 and D36 chicks at 24 h and 36 h, respectively, compared to ND chicks. The mRNA abundance of Olfm4 and Ki-67 was greater in DAF groups upon refeeding, but not until 120 h. The PepT1 mRNA abundance was greater in DAF groups while the abundance of Muc2 mRNA was lower. This difference in mRNA abundance level was more prominent in the duodenum and jejunum. From the analysis of number and distribution of goblet cells found in the upper half and lower half of the villi, expressed as a ratio (VU/VL), a greater ratio was observed in delayed groups compared to ND. In summary, while DAF resulted in altered small intestinal morphology with an effect more pronounced in D36 than D24 chicks, upon refeeding, some genes important to intestinal development were upregulated as a response to the treatment.
Master of Science