A study was conducted to determine the potential role of supplemental valine in formulating practical broiler diets based on recommended levels of digestible amino acids. Six-hundred Cobb 500 d-old male chicks were placed in battery cages (5 chicks/cage). Birds were fed a series of starter dietary treatments from d 1 to 21, and grower dietary treatments from 21 to 35 d. Treatments consisted of diets formulated from recommendations by Rostagno et al. (2005) to provide 90, 95, 100, 105, and 110% of the digestible amino acid requirements with and without supplemental valine for a total of 10 experimental diets. For d 1 to 35, overall performance as noted by average body weight (BW), feed conversion ratio (FCR), and average daily feed intake (ADFI), was significantly higher in the 105 and 110% diets. Individually, the supplemental valine diets showed no significant difference in performance from the non-supplemented valine diets at all levels. The estimated amino acid requirement for male broiler chick performance for BW for 1–21 d was 102.3% of the Rostagno recommendations while the estimated amino acid requirement for BW for 21 to 35 d was 101.1% of the recommendations. The results of this study indicate that broiler diets with supplemental valine performed as well as higher crude protein diets formulated without valine.
