The high cost of feed materials and feed additives in developing nations has elicited interest in the search for sustainable alternatives. Moringa (Moringa oleifera), one of such sustainable alternatives is a tropical plant that has its usefulness investigated in this study. A 42-day study was designed to determine the response of Ross 308 broilers to dietary Moringa oleifera leaf meal supplementation. The Moringa oleifera leaves used for the study were analysed for proximate, mineral and composition as well as phytochemical contents before being incorporated in the diet. Day-old Ross 308 broiler chicks (n = 500) were allotted to five treatments in completely randomized design with each treatment replicated five times and each replicate having 20 chicks. The birds were subjected to diets supplemented with Moringa oleifera leaf meal at 0, 25, 50, 75 and 100 g/kg feed at both starter and finisher stage, respectively and designated as T1, T2, T3, T4 and T5. Moringa oleifera leaf meal level that supported optimum production and physiological variables was modelled using the quadratic function. At day 42, three birds per replicate were slaughtered to evaluate carcass and organ yields. Result of the proximate composition revealed that MOLM is rich in protein (32.37%) and neutral detergent fibre (52.16%). Mineral assay indicated that MOLM was high in calcium, sodium, potassium, sulphur and iron. Daily feed intake (FI), average daily gain (ADG) and feed conversion ratio were the same among the treatments with the exception of starter broilers on diet T1 that had higher ADG (p<0.05) than those on the other diets. Final live weight (FLW), mortality and gizzard weight were influenced (p<0.05) by Moringa oleifera leaf meal supplementation. Moringa oleifera leaf meal supplementation had no effect on parameters measured. Moringa oleifera leaf meal supplementation at 39.98 and 35.80 g/kg feed supported optimum FLW and ADG at starter phase and 46.88 g/kg feed MOLM supported optimum FLW at finisher phase. In conclusion, Moringa oleifera leaf meal is a good source of nutrients and suitable for production of enhanced cut parts in broiler chickens. Birds on 50 and 75 g Moringa oleifera leaf meal/kg feed had higher (p<0.05) packed cell volume (PCV), red blood cell (RBC) and glucose than those on the other 3 treatment diets. The white blood cell (WBC) counts for birds on 50 g Moringa oleifera leaf meal/kg feed were higher (p<0.05) than those on 100 g Moringa oleifera leaf meal/kg feed but similar (p>0.05) to those on 0, 25 and 75 g MOLM/kg feed. Blood platelet count maintained the trend 75 g > 0 g > 50 g > 100 g > 25 g MOLM/kg feed with birds on 75 g Moringa oleifera leaf meal/kg feed being statistically higher (p<0.05) than those on 25, 50 and 100 g MOLM/kg feed. Dietary Moringa oleifera leaf meal supplementation had no significant effect (p>0.05) on haemoglobin (Hb), total serum protein (TSP), albumin, cholesterol and uric acid. Triglyceride (TG) level of birds on 25, 75 and 100 g Moringa oleifera leaf meal/kg feed decreased significantly compared to those on 0 and 50 g MOLM/kg feed. Daily Moringa oleifera leaf meal supplementation had a significant effect (p<0.05) on the differential WBC count. Daily Moringa oleifera leaf meal supplementation with 26.99 g/kg feed and 31.95 g/kg feed respectively supported optimum PCV (38.62%) and glucose (245.42 mg/dl) in Ross 308 broilers. It is, therefore summarized that optimizing MOLM supplementation level in the ration of Ross 308 broilers could assist in improving their productivity. / Agriculture and  Animal Health / Ph. D. (Agriculture)

The increased demand for breast meat of broiler chickens has challenged researchers to investigate management techniques that could be used to increase the production of this valuable commodity. Two experiments were conducted in this study; the first investigated the effect of early feeding of newly hatched broilers on breast meat yield (BMY) at market weight, and the second focused on improving BMY of broilers exposed to short daylengths by feeding higher than conventional levels of dietary protein. In the first experiment, of the 528 eggs set in the incubator, half were placed, at day 18, in hatching trays containing a commercial broiler starter feed whilst the others (the held group) were hatched conventionally. Six chicks from both fed and held groups were sampled at nine-hour intervals from the time that the first chicks hatched for a subsequent period of 36 h. After measuring their body weight these chicks were euthanised and dissected in order to measure their breast and yolk weights. Body protein, lipid and water contents were measured on each chick. At day 21, six birds from the fed and held groups were sampled, and body weight, breast weight and body protein content were measured. The yolk sac weight for fed birds was significantly reduced compared to that of held birds (P < 0.001). Both fed and held birds had the same breast weight at hatch, but at day 21 the mean breast weight of the fed birds was significantly heavier than of held birds (P < 0.05). The birds that were removed first from the hatcher had a reduced breast muscle weight compared to those that were removed last. In the second experiment, a total of 3200 day-old broiler chicks were reared in eight light-tight rooms. Four lighting regimens (12L: 12D, 16L: 8D, 20L: 4D and 24L: 0D) were randomised between rooms, with each light treatment being replicated twice. Each room was divided into four pens and 100 chicks in each pen received one of four dietary protein treatments. At day 35, three birds from each pen were sacrificed so that measurements could be made of breast, thigh, drum and wing weight, and carcass chemical composition. Breast weight increased as daylengths increased except in birds that were fed low protein diet (143 g protein/kg feed). High levels of dietary protein increased breast weight in birds on all other daylengths except for those on 12 h which showed a reduced breast muscle weight when dietary protein content was increased. The results of the first trial suggests that breast meat yield could be improved if newly hatched chicks are offered feed immediately after hatch, however the hypothesis that this increment was due to an overall increase in body protein content in the first few days after hatching could not be corroborated. The results further showed that held birds do not withdraw nutrients from breast muscle to maintain growth at hatch, this is because birds that stayed longer in the hatchery without feed showed increased breast muscle weight compared to those that were removed first. The second trial could not identify a suitable feeding programme to overcome the problem of a lower breast muscle weight that results from the use of 12 h of lighting compared to that when long daylengths are used. Highest breast weight was obtained when birds were fed high protein diet at 20 h. More research is required to further investigate the combined effect of early feeding and daylength on breast meat yield in broiler chickens. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

No abstract available. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

This research reported here was carried out to examine alternatives to antibiotic growth promoters as a result of their being banned in the animal feed industry. Four experiments were conducted to evaluate the efficacy of non-medicated feed additives as replacements for antibiotic growth promoters in broiler feeds. The additives used were enzymes (a new thermo-tolerant powder enzyme called TXAP, phytase, lipase and a new phytase enzyme derived from E. coli called phyzyme XP), organic acid (Acid Pak), prebiotic (Bio-Mos®) and probiotic (All-Lac XCL). Mashed maize-soya based feeds were used in all the experiments, which were conducted in litter-floor pens. The first experiment was a dose-response trial. Broilers in eight replicate pens of 50 males and 50 females were fed unsupplemented feeds and five additional feeds containing increasing levels of TXAP, from 0.5 to 2.5 g/kg to 42 d. The second experiment used enzyme TXAP with two different enzymes (phytase and lipase), individually or in combination. Six replicate pens of 50 males and 50 females were fed either unsupplemented feeds or one of six additional feeds treated with TXAP, lipase, phytase , a combination of TXAP and lipase, a combination of TXAP and phytase or a combination of all the three enzymes . This trial continued for 42 d. In the third experiment three types of TXAP (Lot 1, 2 and 3) were used, with fixed levels of xylanase and amylase but varying levels of protease activities (4000, 2000 and 1000 U/kg for Lot 1, 2 and 3, respectively) in combination with phyzyme XP for 35 d. The fourth experiment used mannan-oligosaccharide (Bio-Mos®), organic acid (Acid pak 2x), probiotic (All Lac XCL 5x), individually or in combination and an antibiotic growth promoter (Zinc bacitracin) for 42 d. The chickens in this experiment were challenged with Clostridium perfringens (CP) at 21, 22 and 23 d to determine the efficacy of these additives for replacing antibiotics in hindering the effects of CP on the villus surface area. The dose-response trial did not show any significant improvement in broiler performance with any level of inclusion of enzyme TXAP. The results from this study showed some beneficial effects with the use of enzyme TXAP when fed alone and at a young age. Its use when combined with other enzymes and at later stages of growth needs further investigation. Feed additives in experiment 4 prevented the negative effects of CP as the treated chickens did not have lesions on their villus surfaces. The conditions under which these trials were conducted appeared to be such that little benefit was derived from the use of any of the feed additives used. It is possible that under less-hygienic conditions such as those in commercial operations greater benefits from these additives may be realised. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.