Effect of dietary lysine to energy ratio on productivity, carcass characteristics and sensory attributes of indigenous Venda chickens.

Abstract

A study was conducted to determine the effect of dietary lysine to energy ratio on productivity, carcass characteristics and sensory attributes of indigenous female Venda chickens aged 8 to 13 weeks. A total of 200 eight-weeks old female Venda chickens were fed isonitrogenous diets but with different lysine to energy — ratios to form dietary lysine to energy ratio treatments of 0.57, 0.62, 0.67 and 0.73 g/MJ ME. A completely randomised design was used. Data on productivity, carcass and meat sensory attributes were determined. All data were analysed using a one way analysis of variance. Treatment means were separated using the least — significant'difference. A quadratic equation was used to determine dietary lysine to energy ratio for optimal response of production variables measured. Results show that feed intake, apparent metabolizable energy intake, growth rate, FCR and live weights were influenced (P<0.05) by dietary lysine to energy ratio. Carcass weight, dressing percentage, breast meat, drumstick, wing, drip loss, meat juiciness and flavour were also influenced (P<0.05) by dietary lysine to energy ratio. However, dietary lysine to energy ratio did not affect (P>0.05) thigh, fat pad, gizzard, liver and heart weights, and tenderness. Carcass weight, dressing percentage, breast meat, drumstick and wing weights were optimized at the same dietary lysine to energy ratio of 0.66. Drip loss, meat juiciness and flavour were optimized at dietary lysine to energy ratios of 0.63, 0.71 and 0.62, respectively. It was concluded that a single dietary lysine to energy ratio of 0.65 optimized growth rate, live weight and ME intake of Venda chickens. Similarly, a single dietary lysine to energy ratio of 0.66 optimized carcass weight and dressing percentage, while a ratio of 0.67 optimized feed intake, breast meat and drumstick weights. Feed conversion ratio, wing weight, meat drip loss, juiciness and flavour of Venda chickens were optimized at different ratios of O.64. 0,60, 0.63, 0.71 and 0.62, respectively. These results have implications on ration formulation for indigenous Venda chickens.