Abstract: There is little information on Lysine (Lys) requirements of mixed-sex broiler chickens during the grower period. An experiment was conducted to determine the digestible Lys requirements of straight-run Ross 308 broilers from 15-28 days of age. Basal diet consisting of wheat, triticale and corn gluten meal was formulated to be adequate in all essential amino acids except for Lys. Graduation levels of supplemental Lys-HCl were added to the basal diet at expense of corn starch generating six treatments to provide a range from 0.60-1.20% of digestible Lys. Both male and female birds were randomized across 48 floor pens (4 replicates and 12 birds per each replicate) in a completely randomized design and each pen was fed one of six amino acid levels from 15-28 days of age. Body weight gain, feed intake, feed conversion, digestible Lys intake and mortality were measured during the experimental period. Body Weight Gain (BWG) and Feed Conversion (FC), Feed Intake (FI) and daily Lys intake responded quadratically to graded levels of digestible Lys (0.60-1.20%). Digestible Lys requirements were estimated using a linear broken-line and quadratic broken-line models. Based on broken-line linear model, digestible Lys requirement for straight-run Ross 308 broilers was determined to be 0.95 and 1.08% for BWG and FC, respectively. However, using broken-line quadratic model, digestible Lys was estimated at 1.05% for BWG.
M. Mehri, H. Nassiri-Moghaddam, H. Kermanshahi and M. Danesh-Mesgaran, 2010. Digestible Lysine Requirements of Straight-Run Broiler Chickens from Fifteen to Twenty-Eight Days of Age. Journal of Animal and Veterinary Advances, 9: 2321-2324.