Thesis (M.A. Agricultural Management (Animal Production)) -- University of Limpopo, 2016 / A total of 320 male and female day old Ovambo and Potchefstroom koekoek (PK) chickens, were randomly assigned to a 2 (breed) × 2 (sex) factorial arrangement in a completely randomised design. Meat quality traits of male and female Ovambo and Potchefstroom Koekoek chickens were evaluated in this comparative study. The chickens were raised from day-old and fed on a commercial grower diet with 11.5 MJ/ME kg DM and 20% crude protein. The carcass traits of the Ovambo and Potchefstroom Koekoek (PK) were similar (P>0.05) except for breast yield. Sex affected on all carcass traits. Breed, sex, and time interactions influenced colour parameters of thigh and drumstick meat except redness (a*) and yellowness (b*) values of chicken breast meat. The pH varied significantly (P<0.05) between the breeds, sex and time period. The sensory evaluations of the chicken breeds were similar (P>0.05). However, tenderness of the breast meat as measured by shear force was higher for PK than that of Ovambo chickens. Fatty acid profiles of the chickens were not affected (P>0.05) by breed or sex. The ratios of n-6 and n-3 fatty acids were significantly lower in both breeds which are desirable in reducing the risk of many heart-related diseases. The information obtained from this study can assist efforts to promote production of indigenous chickens. The information also sheds some light in terms of consumer awareness for healthier meat choices. Keywords: Breed, Carcass traits, Meat colour, meat pH, Fatty acids

Thesis (MSc. Agriculture (Animal Production)) -- University of Limpopo, 2015 / Three experiments were conducted to determine the effect of in ovo glucose injection on egg hatchability, chick hatch-weight, productivity and carcass characteristics of indigenous Potchefstroom koekoek chickens. A complete randomized design was used in all the three parts of the study (from incubation, 1-49 days old unsexed chickens and 50-91 days old female chickens). On day 18 of incubation the developing eggs were subjected to the following treatments: 0- (no glucose or water injected), 0+ (only water injected), 5, 10, 15 or 20 mg of glucose per egg. Each treatment had three replications and there were 20 eggs per replicate. A quadratic model was used to determine in ovo glucose injection levels for optimal egg hatchability, chick hatch-weight and chick to egg weight ratio of Potchefstroom koekoek chickens. In ovo glucose injection improved (P<0.05) egg hatchability, chick hatch-weight and chick to egg weight ratio of the chickens. Egg hatchability, chick hatch-weight and chick to egg weight ratio Potchefstroom koekoek chickens were optimized at different injection levels of 4.50, 10.43 and 12.00 mg of glucose per egg, respectively. Unsexed day-old chicks from the first experiment (according to their initial treatments and replicates) were used in a complete randomized design having six treatments, replicated three times, and having ten birds per replicate. Glucose injection levels increased (P<0.05) feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of female Potchefstroom koekoek chickens aged 1 to 49 days. However, growth rate, live weight, metabolisable energy intake and nitrogen retention of the chickens were optimized at glucose injection levels of 3.92, 4.36, 10.67 and 13.50 mg per egg, respectively. Female chickens from the second part of the study (according to their initial treatments and replicates) were used in a complete randomized design having six treatments, replicated three times, and having five birds per replicate. In ovo glucose injection levels improved (P<0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention of female Potchefstroom koekoek chickens aged 50 to 91 days. However, only feed conversion ratio and metabolisable energy intake of the chickens were optimized at glucose injection levels of 12.15 and 5.57 mg per egg, respectively. Injection level also improved (P<0.05) carcass, breast, v drumstick, thigh, wing, gizzard and liver weights of female Potchefstroom koekoek chickens aged 13 weeks. In ovo glucose injection increased (P<0.05) breast meat tenderness, juiciness and flavour of female Potchefstroom koekoek chickens aged 91 days. However, breast tenderness, juiciness and flavour of female Potchefstroom koekoek chickens were optimized injection levels of 13.50, 19.25 and 10.83 mg of glucose per egg, respectively. No chicken deaths were observe

Indigenous poultry breeds represent an important animal genetic resource. However, their characteristics in respect of performance, product quality, and integument condition are often poorly investigated. Therefore, the local breeds Saxonian chickens (SaChi) and German Langshan bantam chickens (GLB) of different plumage colors were characterized. The high-performing hybrid strain of Lohmann brown chickens (LB) served as the control group. For each group, 60 hens and 6 roosters were studied in an extensive free-range system from 21 to 80 wk of life. The plumage and foot pad quality were scored on 9 distinct observation dates and the measurements of the egg quality were performed at 7 different time periods. The number of eggs per hen housed in the first laying year was significantly lower in the SaChi (146.4 ± 30.8) and the GLB chickens (107.8 ± 20.4) when compared to the LB chickens (295.0 ± 16.8) (P < 0.001). Regarding laying performance, we detected effects of plumage color within both local breeds (P < 0.001). Within 4/7 plumage colors, effects of the breeder were also found (P ≤ 0.037). The eggs of the local chicken breeds showed lower egg weights (P < 0.001), shell breaking strength (P ≤ 0.041), albumen consistency (P < 0.001), and a lower egg shape index (P < 0.001), but higher proportions of yolk (P < 0.001) when compared to the eggs of the LB chickens. The logistic regression models for the plumage and footpad condition demonstrated that the SaChi and GLB hens underwent less plumage loss and footpad swelling than the LB hens (P < 0.001). Overall, this study shows that the laying performance of the local breeds was significantly lower, but there were noticeable advantages in terms of egg composition and animal welfare indicators when compared to a high-performing hybrid strain. In further studies and the use in extensive production systems, the observed performance differences between plumage colors and breeders should be taken into account.