Effect of Different Dietary Lysine to Threonine Ratio on Performance of Cobb 400 Broiler Chicken

摘要

Effects of incremental levels of dietary threonine and different lysine to threonine ratio was evaluated in 1600 one-day-old Cobb 400 chicks divided into four dietary treatments, each consisting of four replicate of 100 chicks. The lysine to threonineratio in the pre-starter, starter and finisher diets were 74, 78, and 78 in TO (control), 70, 73 and 73 in T1, 67, 70 and 70 in T2 and 66, 68 and 70 in T3 group, respectively. Body weight and feed conversion ratio at 42 d as well as the carcass yield and breast meat yield were improved (P<0.05) in the treatments. Across the diets, T2 group performed better (P<0.05) than the Tl and T3 groups. It was concluded that the lysine to threonine ratio 67, 70, 70 for prestarter, starter and finisher diets, respectively may be optimum for cob 400 broilers.