Abstract: The aim of the present study was to determine the effects of different levels of l-lysine HCL on performance and carcass characteristics of broiler chickens (Ross-308) from 1-42 days of old. A basal diet according to NRC was formulated. Four graded supplements of lysine as l-lysine HCL (110, 115, 120 and 125% of NRC) were added to the basal diet. Each experimental diet was fed to 80 chickens in a completely randomized design with 4 replicates for each treatment. Weight gain, feed intake and feed conversion ratio of each pen in starter and grower period were compared. Dietary lysine had a significant effect on body weight, feed intake, feed conversion ratio, breast and abdominal fat percentage (p<0.05). Supplementing of l-lysine HCL to starter and grower diets containing the NRC lysine level significantly improved body weight gain and feed intake (p<0.05). Body weight was maximized in birds fed 110% of the NRC recommendations. Feed conversion ratio were optimized by feeding 110% of the NRC Lysine recommendation. The results of this study indicate that increasing dietary lysine up to 110% of the NRC recommendation significantly increased breast yield in male chicks, with no improvement at higher levels and unsexed birds. Quadratic response curves were fitted to growth performance criteria of chicks. The requirement lysine level by segmented regression (plateau) method for body weight gain and feed conversion ratio in starter and grower period were 106.76, 106.8, 107.39 and 107.14, respectively.
A. Safamehr , A. Azgani and Y. Mehmannavaz , 2008. Effects of Lysine-HCL Supplementation on Performance and Carcass Characteristics of Ross Broilers. Research Journal of Biological Sciences, 3: 1197-1201.