Effect of dietary vitamin D3 supplementation on meat quality of naked neck chickens

Consumers’ interest of indigenous chicken meat is increasing. An experiment was conducted to determine the effect of vitamin D3 supplementation on meat quality of indigenous male naked neck chickens. Different supplementation levels of 0, 2000, 4000, 6000 and 8000 IU of vitamin D3 per kg DM of feed were used. 13 weeks old male naked neck chickens with a mean live weight of 1200 ± 3 g were supplemented with vitamin  D3 for a period of seven days before slaughter. A 2 (cooking or not) x 2 (postmortem agings of 0 or 24 hs) x 5 (vitamin D3 levels) factorial arrangement in a complete randomized design was used for shear force analysis of raw or cooked naked neck chicken meat. A 2 (postmortem agings of 0 or 24 hs) x 5 (vitamin D3 levels) factorial arrangement in a complete randomized design was used for sensory evaluation of the meat. A quadratic equation was used to determine vitamin D3 supplementation levels for optimum shear force value and sensory attributes. Vitamin D3 supplementation did not improve (P>0.05) shear force values of unaged or aged raw and cooked naked neck chicken meat. Shear force values of unaged raw or cooked meat were optimized at different levels of 3735 (r2=0.832) and 2512 (r2=0.669) IU of vitamin D3 per kg DM feed, respectively. Shear force values of aged raw or cooked meat were optimized at different levels of 6728 (r2 =0.274) and 4249 (r2=0.873) IU of vitamin D3 per kg DM feed, respectively. Vitamin D3 supplementation had no effect (P>0.05) on unaged meat tenderness, juiciness and flavour. However, vitamin D3 supplementation improved (P<0.05) aged meat tenderness and flavour. Tenderness, juiciness and flavour of aged naked neck chicken meat were optimized at supplementation level of 6830 (r2=0.839), 6894 (r2=0.683) and 9795 (r2=0.657) IU of vitamin  D3 per kg DM. It was concluded that vitamin D3 supplementation improved tenderness and flavour of aged naked neck chicken meat. However, shear force values of unaged or aged raw or cooked naked neck chicken meat were not improved by vitamin D3 supplementation.Keywords: Shear force, postmortem aging, calpains, connective tissue, tenderness, juiciness, flavorAfrican Journal of Biotechnology Vol. 12(22), pp. 3576-358

Dietary energy level for optimum productivity and carcass characteristics of indigenous Venda chickens raised in closed confinement

A study was conducted to determine dietary energy levels for optimum productivity and carcass characteristics of indigenous Venda chickens raised in closed confinement. Four dietary treatments were considered in the first phase (1 to 7 weeks) on two hundred day-old unsexed indigenous Venda chicks indicated as EVS1, EVS2, EVS3 and EVS4 (11, 12, 13 and 14 MJ ME/kg DM, respectively) and each treatment was replicated five times. In the second phase (8 - 13 weeks), 160 indigenous Venda female chickens, aged eight weeks, were randomly allocated to four dietary treatments and each treatment was replicated five times in a completely randomized design. The diets used in both trials were isonitrogenous but with different energy levels. A quadratic equation was used to determine dietary energy levels for optimum feed intake, growth rate, FCR and ME intake at both the starter and grower phases and the carcass characteristics of the birds at 91 days. Dietary energy levels of 12.91, 12.42, 12.34 and 12.62 MJ ME/kg DM feed supported optimum feed intake, growth rate, FCR and ME intake, respectively, for the starter phase. At the grower phase, dietary energy levels of 12.56, 12.66, 12.62 and 12.71 MJ ME/kg DM feed supported optimum feed intake, growth rate, FCR and ME intake, respectively. Carcass, drumstick, thigh and wing had optimum weights at dietary energy levels of 13.81, 13.23, 13.43 and 13.18 MJ ME/ kg DM, respectively. Thus, dietary energy level for optimization depended on the particular production parameter in question.Keywords: Metabolisable energy, optimization, quadratic equation, digestibilit

Effects of egg weight on hatchability, chick hatch-weight and subsequent productivity of indigenous Venda chickens in Polokwane, South Africa

A study was conducted to determine the effect of egg weight on hatchability, chick hatch-weight, mortality and subsequent productivity of indigenous Venda chickens. Three hundred and sixty indigenous Venda chicken eggs were collected for a period of a week and selection was done based on the weight of the eggs. A complete randomized design was used, with four treatment weights, each with 90 eggs. The four treatment weights were as follows: below 49 g, between 50 and 59 g, between 60 and 69 g, and above 70 g. Egg weight was positively and strongly correlated with egg hatchability (r2 = 0.727) and chick hatch-weight (r2 = 0.953). Heavier-sized eggs hatched chicks had higher mortality rates. Growth rate and live weight of the chickens were optimized at different egg weights of 56 (r2 = 0.657) and 60 (r2 = 0.870) g, respectively, for chickens aged 1 to 7 weeks, and egg weights of 61 g (r2 = 0.514) and 60 g (r2 = 0.948), respectively, for chickens aged 8 to 13 weeks. It is concluded that indigenous Venda chicken egg weight affects hatchability, hatch-weight, mortality and subsequent productivity of the chickens. It is concluded that production variables were optimized at different egg weights. This means that the selection of eggs for incubation will depend on the parameter in question.Keywords: Venda chickens, egg weight for optimal productivity, growth, mortalit

Effect of Aqueous Moringa Oleifera (Lam) Leaf Extracts on Growth Performance and Carcass Characteristics of Hubbard Broiler Chicken

ABSTRACT Two hundred and forty day old broiler chicks were used to investigate the effect of aqueous Moringa oleifera leaf extracts (AMOLE) on growth performance and carcass characteristics of broiler chicken. The birds were randomly allocated into six treatments with four replicates, and each replicate containing 10 broiler chicks; the CRD was used. The treatments contained AMOLE0+ (positive control with antibiotic treatment), AMOLE0- (negative control with ordinary water), AMOLE60 (60 ml/l), AMOLE90 (90 ml/l), AMOLE120 (120 ml/l) and AMOLE150 (150 ml/l) inclusion levels of AMOLE, respectively. Birds on positive control had the highest final body weight and growth rate (2392.00 g and 53.61 g respectively) and the ones on 150 ml/l of AMOLE had the least (2042.00 g and 45.37 g respectively). Results of feed intake showed that birds on positive control had the highest (84.70 g) and the ones on 90 ml/litre of AMOLE had the lowest (73.19 g); while the results of feed conversion ratio indicated that birds on AMOLE90 and AMOLE120 performed better than the positive control treatment. Birds on the AMOLE had similar dressing percentages though that of positive control was highest (94.93 %); while those on AMOLE60 and AMOLE150 had the highest large intestine and lung weights respectively. Aqueous Moringa oleifera leaf extract can be included up to 90 ml/litre in the drinking water of broiler chicken for reduced feed intake (12.83 %) and improved feed conversion efficiency (9.11) thus, AMOLE can be used to replace synthetic antibiotics as growth promoter