Effect of different lysine levels on Arian broiler performances

An experiment was conducted to evaluate the performance and carcass yield of Arian male broilers fed diets (starter and grower) with different levels of lysine requirements, high lysine (120% National Research Council, NRC), medium lysine (110% NRC), standard (100% NRC) and low lysine (90% NRC) in a completely randomized experimental design. All diets were isocaloric and isonitrogenous. In broilers receiving 120% of NRC Lysine, body weight in 42 d significantly increased by 248 g compared with standard lysine diet. Feeding broilers with high lysine diets (120% NRC) significantly increased feed intake and body weight gain (22-42 and 0-42 day of age) compared with standard group (P<0.05). Body weight was significantly difference in all of weeks of trail (P<0.05). Lysine levels had no effect on feed conversion ratio. This study showed that increasing lysine level (120% NRC) in diet significantly increased abdominal fat pad, gizzard and heart weight compared with standard group (P<0.05).The results of this study suggest that additional lysine at the level of 120% of NRC in starter and grower diets optimized body weight gain in Arian broiler, whereas reductions in lysine level reduced growth and live weight.