Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2018 / Two experiments were conducted to determine the effect of replacing maize meal with a low tannin sorghum meal (Macia) on productivity, gut morphology, carcass characteristics and bone morphometrics of Ross 308 broiler chickens aged one to 42 days. In each experiment, a total of 160 Ross 308 broiler chickens were assigned to a complete randomized design with 5 treatments, replicated 4 times with 8 chickens per replicate. Five diets were formulated to contain sorghum replacement levels at 0, 25, 50, 75 and 100% to meet the nutrient requirements of Ross 308 broiler chickens. Data was analysed using statistical analysis of variance. The first experiment determined the effect of replacing maize meal with a low tannin white sorghum meal on productivity and gut morphology of unsexed Ross 308 broiler chickens aged 1 to 21 days. Feed intake, growth rate, feed conversion ratio, live weight, N-retention, caecum and large intestine digesta pH, large intestine lengths, crop, gizzard, caecum and large intestine weights, gut intestinal villi height, crypt depth and villi height to crypt depth ratio of unsexed Ross 308 broiler chickens were not affected (P>0.05) by the treatment effects. However, replacement of maize meal with sorghum meal improved (P<0.05) metabolisable energy intake and small intestine digesta pH values. It was concluded that maize meal can be replaced by a low tannin white sorghum meal in the diet without adverse effects on unsexed Ross 308 broiler chickens aged one to 21 days. The second experiment determined the effect of replacing maize meal with sorghum meal on productivity, gut morphology, carcass characteristics and bone morphometrics of Ross 308 male broiler chickens aged 22 to 42 days. Replacing maize meal with sorghum meal had no effect (P>0.05) on feed intake, feed conversion ratio (FCR), live weight and nitrogen retention (N-retention) of male Ross 308 broiler chickens aged 22 to 42 days. Replacing maize meal with sorghum meal improved (P<0.05) ME intake and growth rate of the chickens. Caecum and large intestine digesta pH, GIT, caecum and large intestine lengths, small intestine, caecum and large intestine weights, gut intestinal villi height, crypt depth and villi height to crypt depth ratio, drumstick, thigh and wing weights, drumstick, thigh and wing colour, meat sensory evaluation, meat pH and bone morphometrics of male Ross 308 broiler chickens were not affected (P>0.05) by replacement of maize meal with sorghum vii meal. It was concluded that maize meal can be replaced by a low tannin white sorghum meal at 25, 50, 75 and 100% levels without causing adverse effects on productivity and carcass characteristics of male broiler chickens aged 22 to 42 days. Key words: Low tannin sorghum meal, Maize meal, Broiler chickens, Growth rate, Carcass characteristics. / National Research Foundation (NRF)

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)

Diss. Uppsala : Uppsala universitet, 2009.

Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2019 / Two experiments were conducted to determine the effect of dietary methionine level on productivity and carcass characteristics of Ross 308 broiler chickens. In each experiment, the diets were isocaloric and isonitrogenous but with different dietary methionine levels. Five diets were formulated to contain dietary methionine levels of 4, 5, 6, 8 or 9g/kg DM. The first experiment commenced with 300 unsexed Ross 308 broiler chickens with initial average live weights of 42 ± 2g per chicken. The chickens were randomly assigned to five treatments with five replications, resulting in 25-floor pens with 12 chickens per replicate. The second experiment commenced with 150 male Ross 308 broiler chickens with initial average live weight of 637 ± 12g per chicken. The chickens were randomly assigned to five treatments with three replications, resulting in 15-floor pens with 10 chickens per replicate. A complete randomized design was used in each experiment. Data was analysed using the General Linear Model (GLM) procedures of the statistical analysis of variance, Version 9.3.1 software program. Where there were significant differences, mean separation was done using the Tukey test at the 5% level of significance. A quadratic regression model was used to determine the optimal productivity of the chickens while a linear model was used to determine the relationships between dietary methionine level and responses by the chickens in the variables measured. The treatments for the first experiment were UM4 (4g methionine/kg DM), UM5 (5g methionine/kg DM), UM6 (6g methionine/kg DM), UM8 (8g methionine/kg DM) and UM9 (9g methionine/kg DM). Feed intake, growth rate, feed conversion ratio (FCR), metabolisable energy intake and nitrogen retention of unsexed Ross 308 broiler chickens aged one to 21 days were not affected (P>0.05) by dietary methionine level. Similarly, dietary methionine level did not have any effect (P>0.05) on diet crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF) and fat digestibilities in unsexed Ross 308 broiler chickens aged 14 to 21 days. Dietary methionine level did not have any effect on live weights of broiler chickens at 21 days. Live weights of unsexed Ross 308 broiler chickens aged 7 or 14 days were not improved (P>0.05) by increasing dietary methionine level from 4 to 9g/kg DM. Crop, gizzard and small intestine weights and crop, proventriculus and gizzard digesta pH values of unsexed Ross 308 broiler chickens aged 21 days were not affected v (P>0.05) by dietary methionine level. Similarly, dietary methionine level did not improve (P>0.05) caecum and large intestine lengths of unsexed Ross 308 broiler chickens aged 21 days. However, dietary methionine level affected (P<0.05) dry matter (DM) and ash digestibilities of unsexed Ross 308 broiler chickens aged 14 to 21 days. Proventriculus and large intestine weights, gastrointestinal tract and small intestine lengths of unsexed Ross 308 broiler chickens aged 21 days were improved (P<0.05) by increasing dietary methionine level. In addition, increasing dietary methionine level increased (P<0.05) small and large intestine digesta pH values of broiler chickens aged 21 days. Thus, dry matter digestibility, live weights at day 7 ad 14, caecum length, large intestine length and digesta pH were optimized at different dietary methionine levels of 7.26, 5.29, 4.99, 6.80, 4.84 and 6.37g/kg DM feed, respectively. The treatments for the second experiment were MM4 (4g methionine/kg DM), MM5 (5g methionine/kg DM), MM6 (6g methionine/kg DM), MM8 (8g methionine/kg DM) and MM9 (9g methionine/kg DM). Dietary methionine level did not have effect (P>0.05) on feed intake of male Ross 308 broiler chickens aged 6 weeks. However, dietary methionine level improved (P<0.05) feed intake of male Ross 308 broiler chickens aged 4 or 5 weeks. Live weights of male Ross 308 broiler chickens aged 28 days were not affected (P>0.05) by dietary methionine level. However, live weights of male Ross 308 broiler chickens aged 35 and 42 days were affected (P<0.05) by dietary methionine level. Similarly, dietary methionine level affected (P<0.05) DM, CP, ADF, NDF, fat and ash digestibilities of male Ross 308 broiler chickens aged 35 to 42 days. Thus, dietary methionine levels of 6.93, 7.70, 6.85 and 11.27g/kg DM optimized dry matter, CP and fat digestibilities, and live weight of male broiler chickens aged 42 days. Dietary methionine level did not affect (P>0.05) FCR, growth rate and metabolisable energy intakes of male Ross 308 broiler chickens. Increasing dietary methionine level from 4 to 9g/kg DM improved (P<0.05) nitrogen retention of male Ross 308 broiler chickens aged 22 to 42 days. Dietary methionine level did not have any effect (P>0.05) on proventriculus, gizzard, caecum and large intestine weights, caecum, small and large intestine lengths, and crop, gizzard, caecum and large intestine digesta pH values of male Ross 308 broiler chickens aged 42 days. Crop and small vi intestine weights and gastrointestinal tract lengths of male Ross 308 broiler chickens aged 42 days were improved (P<0.05) by dietary methionine level. Similarly, dietary methionine level affected (P<0.05) proventriculus and small intestine digesta pH values of male Ross 308 broiler chickens aged 42 days. Thus, dietary methionine levels of 6.558 and 7.851g/kg DM optimized broiler chicken crop weight and GIT length. Dietary methionine level affected (P<0.05) carcass organ weights of male Ross 308 broiler chickens aged 42 days. Increasing dietary methionine level increased chicken breast meat weight. However, there was no clear trend for the other carcass organs. Meat flavour and shear force values of male Ross 308 broiler chickens aged 42 days were not affected (P>0.05) by dietary methionine level. However, dietary methionine level affected meat tenderness and juiciness. Thus, dietary methionine levels of 10.09 and 13.32g/kg DM optimized broiler chicken meat tenderness and juiciness. . / National Research Foundation (NRF) and VLIROUS

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1979 L37 / Master of Science

published_or_final_version / abstract / Zoology / Master / Master of Philosophy

published_or_final_version / abstract / Zoology / Master / Master of Philosophy

published_or_final_version / Orthopaedics and Traumatology / Master / Master of Philosophy

Dressed, bagged whole chickens from three Oregon and several out-of-state processors were purchased from retail markets in each season in 1988. Birds were stored at 3°C for 6 days. Total aerobic microorganisms, total psychrotrophic microorganisms, pseudomonads and fluorescent pseudomonads were determined by appropriate procedures. Total aerobic microorganisms and psychrotrophic microorganisms were counted on standard plate count agar with incubation at 20°C for 3 days and at 5°C for 7 days, respectively. Two media, King's B medium and CFC medium, were used in counting pseudomonads. Fluorescent colonies were observed on King's medium under ultraviolet light. A simple slime smear test was used to determine the sliminess. Sensory evaluation was done by thirteen panelists using 9-point scales. The flavor of cooked white and dark meat and skin, the flavor intensity of cooked white and dark meat and skin, the aroma of raw and simmered meat, the aroma intensity of raw and simmered meat and raw sliminess were evaluated. Simple regression analysis was used to determine the relationships between the microbial parameters and sensory evaluations. The paired t test was used in determining the difference between counts on King's medium and CFC medium. A significance level of 95% was set for all tests. Correlation coefficients were also calculated. All the microbial counts were at or below 10⁷/cm², which indicated from literature comparisons that most of the fryers purchased from retail markets and stored for six days were of acceptable quality. The season had no significant effect on the microbial counts and sensory qualities. The means of flavor of cooked meat and skin and aroma of raw and simmered meat were all above fair. Only the raw aroma intensity was significantly (p<0.05) and strongly correlated (r=-0.88) to the aroma quality. Relationships between microbial counts and flavor of cooked meat and aroma of raw and simmered meat were all significant but the correlations were weak. The narrow range of microbial counts may explain the weakness of the correlations found. The slime smear tests had a positive relationship (p<0.05) to the raw sliminess score by panelists, total aerobic microorganisms, total psychrotrophic microorganisms, pseudomonads, and fluorescent pseudomonads. / Graduation date: 1990