Estimation of Digestible Lysine Requirements of Japanese Quail during the Starter Period

The aim of this study was the estimation of digestible lysine requirements of Japanese quail during the 7-21d period. Graduation level of L-lysine. HCL were added to the basal diet at the expense of corn starch to create different levels of digestible lysine ranged from 0. 75 to 1. 35% of diet. Growth performance and carcass composition were evaluated during the experiment. The results showed that incremental levels of digestible lysine significantly affected the body weight gain (BWG)، feed conversion ratio (FCR)، feed intake (FI)، breast meat yield (BMY) and thigh meat yield (TMY). Either linear broken- line or quadratic broken line model were used to get break points of digestible lysine as a requirement. Based on linear broken line analysis، the break points for FCR and BMY were 0. 99 and 1. 04 % of diet، respectively. Using the quadratic broken-line model، the estimated Lys requirements for BWG، FCR، and BMY were 1. 11، 1. 04، and 1. 15% of diet، respectively. The results showed that the Lys needs for optimum BMY was higher than BWG and FCR.