Thesis (M. Tech. Agriculture, Tshwane University of Technology, 2011. / To increase local growth linkages of smallholder broiler enterprises in rural areas a single-phase, on-farm processed, mash diet, consisting of boiled and ground full-fat soya beans and ground yellow maize grain fortified with lysine, methionine and selected mineral nutrients was first developed and then tested. Financial analysis showed that net operating expenses of broiler enterprises that used the experimental diet were higher than those of similar enterprises using the control diet, but differences in net operating income were only significant in one of the two runs of the experiment. The main economic benefit of using the experimental diet was the added value to the local economy, which increased from 20 % of the retail value of broiler chickens in the case of enterprises using the control diet to 70 % when using the experimental diet.

The potential of lignin and mannanoligosaccharides (MOS), as alternatives to antibiotic growth promoters was evaluated in broilers. Dietary treatments included: (1) negative control (CTL-, antibiotic free); (2) positive control (CTL+, 11 mg/kg virginiamycin); (3) MOS (diet 1 + Bio-Mos: 0.2% to 21 d and 0.1% thereafter); (4) LL (diet 1 + 1.25% Alcell lignin); (5) HL (diet 1 + 2.5% Alcell lignin). Bodyweight and feed conversion were not different when broilers were fed the CTL+, MOS, LL or HL diet. Birds fed MOS or LL had increased jejunum villi height (P < 0.05) and greater goblet cell number per villus (P < 0.05) when compared to those fed the CTL+ diet. MOS and LL increased (P < 0.05) the cecal populations of Lactobacilli and Bifidobacteria when compared to CTL+ fed birds. However, Lactobacilli and Bifidobacteria loads were lowest (P < 0.05) in birds fed the CTL+ or HL diet. Litter E. coli load was reduced (P < 0.05) when birds were fed MOS than when fed the CTL+ diet, but comparable to LL or HL fed birds. In birds challenged with pathogenic strains of E. coli (O2 and O88 serotypes) and fed the MOS or HL diet, the cecal population of total E. coli was lower (P < 0.05) than those fed the CTL+ diet; LL fed birds tended to have lower E. coli load than CTL+ fed birds. In summary, birds fed the MOS or LL diet had comparative advantage over CTL+ fed birds as evidenced by increased cecal populations of Lactobacilli and Bifdobacteria, increased villi height and greater goblet cell number in the jejunum, lower E. coli load in the litter, and lower cecal population of E. coli after an in vivo challenge with pathogenic strains of E. coli. Therefore, MOS and lignin could be regarded as natural alternatives to antibiotic growth promoters in poultry production. / Key words. Antibiotics, mannanoligosaccharides, lignin, gut health, broilers.

No description available.

Call number: LD2668 .T4 1985 Z58 / Master of Science

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.

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

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.

Three experiments were conducted to study the nutritional value of poultry litter in ruminants and poultry. In the first experiment, eight yearling wethers were used in a series of three metabolism trials to study the utilization of the nitrogen in autoclaved peanut hull broiler litter containing 32.6% crude protein (dry matter basis). Poultry litter nitrogen replaced 25, 50 and 100% of the nitrogen of a purified diet containing isolated soybean protein as the nitrogen source. Apparent digestibility of crude protein in the rations decreased significantly at each increase of litter nitrogen level beyond 25%. However, the depression of crude protein digestibility at 50% litter nitrogen level was small. Digestibility of the litter nitrogen, calculated by difference, was 67 and 64%, respectively at 25 and 50% level of the nitrogen, which were not much lower than 71% when only soy protein was used. Nitrogen retention and percent utilization of absorbed nitrogen were significantly lower at the 100% litter-N level than when no litter was used. There were no consistent differences in the nitrogen fractions of the rumen fluid and blood plasma among the rations. In the second experiment, three digestion and metabolism trials were conducted with 10 yearling wethers to study the protein and energy utilization of autoclaved peanut hull and woodshaving broiler litters when each was incorporated in corn-hay natural ration at levels of 25 and 50 percent. Apparent digestibility of crude protein did not show any significant difference among the rations. Crude fiber digestibility of the litter rations was higher than that of the control ration. Dry matter, NFE and energy digestibility were lower (P<.01) for the litter rat:ons and decreased significantly when the litter level in the ration was increased from 25 to 50%. No significant difference was observed in nitrogen retention, due to kind or level of litter in the rations. Crude fiber digestibility, calculated by difference, was significantly depressed when the level of litter was increased from 25 to 50%. There were no other significant differences in digestibility between kind or level of litter. The apparent digestibility of crude protein was 71.7%. Digestible protein content (on dry matter basis) for peanut hull and wood shaving litter were 23 and 22%, respectively. The average TDN value for ooth kinds of litter was 60% (dry basis). Average digestible energy values (kcal./kg. on dry matter basis) were 2472 and 2407 respectively for peanut hull and wood shaving litter. The corresponding values for metabolizable energy were 2212 and 2150 kcal./kg. There was no significant difference in digestible protein, TDN, digestible energy, and metabolizable energy values due to kind or level of litter. The third experiment was conducted to study the value of different levels of processed peanut hull litter as a partial protein supplement in a practical type broiler ration. When 1/6 or 1/5 of the protein in the basal diet was replaced with litter crude protein by the inclusion of 13.9 or 16.7% litter in the diet, there was no significant difference in rate of gain, compared to the control. When 1/4 of protein in the basal diet was replaced by litter crude protein (20.8% litter in the diet), a significant growth depression resulted. Feed efficiency of the litter fed groups was significantly lower than that of groups on the basal diet. / Ph. D.

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

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