Graduation date: 1993

Broiler production is an important animal production enterprise with potential to make high returns. Increasing feed efficiency and early body weight gain has always been a top priority in the broiler industry. The general objective of broiler nutrition is to maximise production performance and profitability . Nutrition is of major importance in raising chicken, and feed is a major input in poultry production systems, accounting for over 60% of total production costs in commercial poultry sector Renkema (1992). The cost of feed is therefore often a constraint especially in developing countries. For instance, Onyenokwe (1994) observed that high cost of feed ingredients in many African countries has caused many poultry farmers to abandon the industry. The continued rise in feed prices is due to competition for some of the ingredients with human e.g. sorghum, wheat and maize. Broiler farmers are therefore forced to use combinations of feed ingredients of low cost to obtain savings and avoid any further loss of profits. It is therefore important to give special attention to feed and feeding since the rate of feed consumption increases rapidly with advancing age of the birds and good nutrition is reflected in the bird's performance and its products. The profitability of a broiler enterprise depends on the efficient conversion of feed to meat. Broilers have the ability to convert the feeds into meat with a high efficiency. For instance Morris and Njuru (1990) reported that broilers have much higher daily rates of protein deposition than layer chicken strains. This implies that fast-growing strains would require greater daily protein intakes than slow-growing ones. In the past, the major criteria for assessing the performance of broilers has been growth rate and feed conversion ratio (FeR). Diet specifications and feeding programmes have been aimed at maximising these two parameters whereby overall flock performance is calculated based on the total weight of chicken produced from total feed deliveries. With the new developments in understanding of nutritional factors affecting broiler growth and carcass composition, it is now possible to apply sophisticated and yet efficient approaches to feeding broilers. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

This study was conducted to investigate the effects of varying levels of dietary lysine and feed allocation, on the performance of female broiler breeders. In trial 1, 900 Cobb breeders from 26 to 45 weeks of age were used. The first four treatments had a fixed level of lysine throughout the experimental period, with 1200, 1070, 930 and 800 mg Lysine/bird/day and the last two treatments had their levels of lysine changed every two weeks, with treatment five started off with 1200 mg lysine/bird/day followed by a gradual decrease up to 975 mg lysine/bird/day at 45 week old, while treatment six started with the lowest level of lysine, 800 mg/bird/day and at 45 week old the intake was 1025 mg/bird/day. The rations provided 1900KJ ME/ day, the birds received 160 g of feed/day. Dietary lysine did not affect body weight, egg production, or egg composition. There were no significant differences in age at 50%, or peak production. Birds receiving 1070 and 1025 mg lysine/bird.day had a slightly, but not significantly, higher production in the current study. Birds receiving 1200 mg lysine/bird.day had the highest body weight and the lowest egg production. In trial 2, 900 broiler breeder hens were used. Protein intake and feed allocation were changed for each treatment at 26, 38 and 50 weeks and ending at 60 weeks. Birds on T1 were fed a constant CP content (145 g protein/kg) but a decreasing feed allocation (175 to 145 g/d). Those on T2 had a constant feed allocation (160 g/d) and a decreasing CP (166 to 124 g/kg) while those on T3 had varying levels of protein (166, 124 and 166 g/kg) and feed allocation (160, 160, 145 g/d). Mean cumulative protein intakes were 5.2, 5.3 and 4.8 kg/bird and mean energy intakes were 417, 412 and 402 MJ/bird for T1, T2 and T3 respectively. Body weights differed significantly at the end of the trial (P<0.05) with T2 showing the highest weight gain. However, egg production, egg weight and egg output were not affected by treatment. These breeders did not benefit from the additional protein and energy provided in the first and second periods by T1 and T2 (vs. T3), nor did they benefit from the additional energy provided in the final ten weeks of production by T2. / M.Sc.Agric. University of KwaZulu-Natal, Pietermaritzburg 2013.

Thesis (BSc. Agriculture (Animal Production)) -- University of Limpopo, 2019 / An experiment was conducted to determine the effect of bovine colostrum feeding period after hatching on performance and carcass characteristics of male Ross 308 broiler chickens. The experiment was based on 0, 12, 24, 36, 48 and 72 hours of liquid bovine colostrum feeding after hatching of broiler chickens. The experiment commenced with 180 male Ross 308 broiler chicks with an initial live weight of 42 ± 2g per bird and was carried out for six weeks. The chicks were randomly assigned to six treatments with three replications, resulting in 18-floor pens with 10 chicks per replicate. A complete randomized design was used in this experiment. Data was analysed using the General Linear Model (GLM) procedures of the Statistical Analysis of system, Version 9.3.1 software program. Where there were significant differences, mean separation was done using the Turkey test at the 5% level of significance. A quadratic regression model was used to determine the optimum productivity of the experiment while a linear model was used to determine the relationships between bovine colostrum feeding period and responses in the variables measured. Feed intake during Week 1, growth rate during Week 3 and feed conversion ratio (FCR) during Weeks 2 and 3 of the growing period of male Ross 308 broiler chickens were not affected (p>0.05) by bovine colostrum feeding periods after hatching. Similarly, bovine colostrum feeding had no effect (p>0.05) on diet dry matter (DM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and ash digestibilities in male Ross 308 broiler chickens aged 14 to 21 days. Bovine colostrum feeding period after hatching had no effect (p>0.05) on nitrogen retention (N-retention) in male broiler chickens aged one to 21 days. Similarly, gut organ digesta pH, length and weight of male Ross 308 broiler chickens aged 21 days were not improved (p>0.05) by bovine colostrum feeding after hatching. However, bovine colostrum feeding improved (p<0.05) feed intake during Weeks 2 and 3 of the growing period of male Ross 308 broiler chickens. Similarly, bovine colostrum feeding after hatching improved (p<0.05) crude protein (CP) digestibility in male broiler chickens aged 14 to 21 days. Metabolisable energy (ME) intake of male Ross 308 broiler chickens aged one to 21 days was improved (p<0.05) by bovine colostrum feeding period after hatching. Similarly, growth rate of male broiler v chickens during Weeks 1 and 2 was improved (p<0.05) by colostrum feeding after hatching. Feed conversion ratio of male broiler chickens during Week 1 was improved (p<0.05) by bovine colostrum feeding period after hatching. Bovine colostrum feeding after hatching improved (p<0.05) live weight of male Ross 308 broiler chickens at the ages of 7, 14 and 21 days. Nitrogen retention and FCR of male Ross 308 broiler chickens aged 22 to 42 days were not affected (p>0.05) by bovine colostrum feeding after hatching. In addition, live weights of male Ross 308 broiler chickens aged 35 and 42 days were not affected (p>0.05) by bovine colostrum feeding period after hatching. Similarly, bovine colostrum feeding had no effect (p>0.05) on gut organ digesta pH, large intestine lengths, breast and drumstick weights and breast meat juiciness of male Ross 308 broiler chickens aged 42 days. However, bovine colostrum feeding improved (p<0.05) feed intake and growth rate of male Ross 308 broiler chickens aged 22 to 42 days. Live weights of male Ross 308 broiler chickens aged 28 days were improved (p<0.05) by bovine colostrum feeding period after hatching. Similarly, bovine colostrum feeding after hatching did not affect (p<0.05) diet DM, CP, NDF, ADF and ash digestibilities in male Ross 308 broiler chickens aged 35 to 42 days. Metabolisable energy intake of male broiler chickens aged 22 to 42 days was improved (p<0.05) by bovine colostrum feeding period after hatching. Similarly, GIT, small intestine and caecum lengths and crop, proventriculus, gizzard, small intestine, caecum, large intestine, carcass and thigh weights of male Ross 308 broiler chickens aged 42 days were improved (p<0.05) by bovine colostrum feeding after hatching. Bovine colostrum feeding after hatching improved (p<0.05) breast meat tenderness, flavour and shear force of male Ross 308 broiler chickens aged 42 days. It is concluded that reasons for differing responses to bovine colostrum feeding periods of up to 72 hours after hatching are not clear. Therefore, further studies in which longer bovine colostrum feeding periods are used after hatching are recommended. / National Research Foundation (NRF)

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 (M.A. (Agricultural Management) -- University of Limpopo, 2020 / Two experiments were conducted to determine the effect of natuzyme50® supplementation on fibre digestion, growth and carcass characteristics of Ross 308 broiler chickens aged one to 42 days. The first experiment determined the effect of natuzyme50® supplementation on feed intake, growth and live weight of unsexed Ross 308 broiler chickens aged one to 21 days. Unsexed day old chicks were assigned to 4 different natuzyme50® supplementation levels of 0.0 (UNZ0), 0.75 (UNZ0.75), 1.0 (UNZ1.0) and 1.5 (UNZ1.5) g/kg DM feed, replicated 4 times and each replicate having 10 chicks. A general linear model (SAS, 2008) was used to analyse the data. Ross 308 broiler chickens on a diet supplemented with 1.5g of natuzyme50® per kg DM had higher (P<0.05) DM feed intake than those on a diet not supplemented with natuzyme50®. Natuzyme50® supplementation did not (P>0.05) have any significant effect on growth rate of unsexed Ross 308 broiler chickens aged one to 21 days. Unsexed broiler chickens on a diet supplemented with 1.5g of natuzyme50® per kg DM had higher (P<0.05) live weights than those on a diet not supplemented with natuzyme50® at the age of 21 days The second experiment determined the effect of natuzyme50® supplementation on feed intake, growth performance and carcass characteristics of male Ross 308 broiler chickens aged 22 to 42 days. The chickens aged 22 days were assigned to 4 natuzyme50® supplementation levels of 0.0 (MNZ0), 0.75 (MNZ0.75), 1.0 (MNZ1.0) and 1.5 (MNZ1.5) g/kg DM feed, replicated 4 times and each replicate having 6 chickens. The diets were isocaloric and isonitrogenous. A general linear model (SAS, 2008) was used to analyse the data obtained. Natuzyme50® supplementation level had no effect (P>0.05) on feed intake of male Ross 308 broiler chickens aged 22 to 42 days. However, natuzyme50® supplementation level had effect (P<0.05) on growth rate of male Ross broiler chickens aged 22-42 days. Male Ross 308 broiler chickens on a diet supplemented with 1.5g of natuzyme50® per kg DM had higher (P<0.05) growth rates than those on a diet supplemented with 1.0g of natuzyme50® per kg DM. However, the significant differences did not extend to birds on a diet not supplemented with natuzyme50®, diets supplemented with 0.75 or 1.5g of natuzyme50® per kg DM which vi showed similar (P>0.05) growth rates. Natuzyme50® supplementation levels used had no effect (P>0.05) on carcass, breast and drumstick weights of male Ross 308 broiler chickens. Natuzyme50® supplementation levels had no effect (P>0.05) on meat juiciness. However, natuzyme50® supplementation improved (P<0.05) meat tenderness and flavour. Increasing natuzyme50® level of supplementation decreased (P<0.05) meat shear force values. It is concluded that natuzyme50® supplementation improved (P<0.05) meat tenderness and flavour, and reduced meat shear force values of male Ross 308 broiler chickens. However, further studies are recommended to ascertain the current results. / Edu-loan

(M.Sc. (Animal Production)) -- University of Limpopo, 2014 / Two experiments were conducted to determine the effect of dietary threonine level on productivity and carcass characteristics of indigenous Venda chickens. In each experiment the diets were isocaloric and isonitrogenous but with different dietary threonine levels. A complete randomized design was used in both experiments, the starter (1-7 weeks old unsexed chickens) and finisher (8-13 weeks old female chickens) experiments. The treatments were CT4 (4 g of threonine/kg DM), CT5 (5 g of threonine/kg DM), CT6 (6 g of threonine/kg DM), CT7 (7 g of threonine/kg DM) and CT8 (8 g of threonine/kg DM). A quadratic type of equation was used to determine dietary threonine levels for optimal feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention of unsexed Venda chickens aged one to seven weeks. Dietary threonine level affected (P<0.05) feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention. However, feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of indigenous Venda chickens were optimized at different dietary threonine levels of 6.218, 6.437, 6.331, 6.655, 5.979 and 6.158 g/kg DM feed, respectively. Dietary threonine level did not affect (P>0.05) mortality rate of the chickens. The treatments for the second experiment were FT4 (4 g of threonine/kg DM), FT5 (5 g of threonine/kg DM), FT6 (6 g of threonine/kg DM), FT7 (7 g of threonine/kg DM) and FT8 (8 g of threonine/kg DM). Dietary threonine level had effect (P<0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of female Venda chickens aged eight to 13 weeks. Feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention of chickens were optimized at dietary threonine levels of 6.054, 6.142, 6.442, 6.201, 5.72 and 6.088 g/kg DM, respectively. However, dietary threonine level had no effect (P>0.05) on pH values of crop, proventriculus, gizzard, small intestine, large intestine and caecum of female Venda chickens aged 91 days. Carcass weights of female Venda chickens were affected (P<0.05) by dietary threonine level. Carcass, breast, drumstick, thigh, gizzard and liver weights of female Venda chickens aged 91 days were optimized at dietary threonine levels of 6.183, 6.201, 5.712, 5.847, 4.820 and 6.180 g/kg DM, respectively. Dietary threonine level v had effect (P<0.05) on crude protein and threonine contents of female Venda chicken meat. Meat crude protein and threonine contents of female Venda chickens aged 91 days were optimized at dietary threonine levels of 5.9 and 5.7 g/kg DM, respectively. Dietary threonine level had no effect (P>0.05) on meat flavour, tenderness and juiciness of female Venda chickens. However, meat flavour, tenderness and juiciness of female Venda chickens aged 91 days were optimized at dietary threonine levels of 5.977, 6.103 and 5.977 g/kg DM, respectively. No chicken deaths were observed. / National Research Foundation (NRF)

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. / 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.

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.