Optimizing digestible threonine requirements for commercial broiler performance, immunological and carcass parameters

A total of 250 commercial broiler birds (Ven Cobb) were used in the present research to assess the digestible threonine graded concentrations (100, 75, 70, 65, and 60% of the digestible lysine) in order to optimize the threonine requirements for improving the productive performance in commercial broiler diets. Using a completely random design (CRD) the chicks were divided into five treatments, each containing ten replicates and each with five chicks. Throughout the experiment, a corn soy based diet was prepared and supplemented with digestible threonine at graded concentration of digestible Lysine. The amount of digestible threonine in the broiler diet had no effect on feed intake and body weight gain in any of the growth phases. However, during the pre-starter and starting phases, FCR was significantly (p