Assessment of digestible amino acid requirement in White leghorn Layers based on production performance at low protein levels in diet

To understand the optimal requirement of d.lysine and threonine in White Leghorn (WL) layers (25-44 weeks), two independent experiments were executed. For d. lysine study, birds (N=528) categorized into eleven dietary groups (11×6×8) fed with different protein levels (13.36 15.78%) each containing five concentrations Lys. optimize Thr, (N=390) allotted to thirteen (13×5×6) these diets formulated by fixing at 0.65 0.60% 13.36 15.78% respectively. Threonine was supplemented both graded lysine. Basal 0.70% 17% protein; 66% served as corresponding controls. Egg production response supplemental Lys quadratic. Net feed efficiency egg mass indices linear Supplementation whereas, it quadratic for economic parameters. In conclusion, supplementation 0.60%; 69 72% Thr % low high is better WL tropics.