An experiment was carried out at Faculdade de Medicina Veterinária e Zootecnia-UNESP-Botucatu to evaluate the effect of high dietary lysine levels and sex on broiler performance, carcass and breast meat yield. Two thousand Ross day-old chicks were reared in a 2x2 randomized factorial design (two sex and two dietary lysine levels). Starter diets (0 - 21 days) and grower diets (22 - 42 days) were formulated to comply with 100% of NRC (1994) lysine requirements, while lysine level of finisher diet (43 - 49 days) was 120% of NRC (1994) recommendation. Broilers were processed at 28, 35, 42 and 49 days for carcass and breast meat yield evaluation. Dietary lysine level didn’t effect (p>.05) weight gain, feed conversion and carcass yield but high lysine levels resulted in less abdominal fat than low lysine level, in females. It was concluded that NRC (1994) lysine requirements are adequate to maximize carcass and breast meat yield.
performance; broilers; lysime; carcass yield
