Responses of broilers to dietary protein levels and amino acid supplementation to low protein diets at various environmental temperatures

This study sought to determine specific correlations between dietary protein, amino acids, and increasing environmental temperatures for broilers. Male broilers were housed in six different constant environmental temperatures ranging from 21.1 to 35 degrees C and fed a series of 3250 kcal ME grower diets with increasing protein levels, or low protein diets with 90, 100, or 110% NRC recommended levels of methionine, lysine, tryptophan, arginine, and threonine. The broilers housed in temperatures below 25.3 degrees C showed increased weight gains with increased CP diets, whereas birds housed in temperatures greater than 26.7 degrees C showed depressed gain with CP diets greater that 20%. Broilers fed the 16 and 18% diets did not show increased gains with the five added essential amino acids under any temperature conditions, indicating that other amino acids were limiting.