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 p rotein, amino acids, and increasing environmental temperatures for bro ilers. Male broilers were housed in six different constant environment al 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 prote in diets with 90, 100, or 110% NRC recommended levels of methionine, l ysine, tryptophan, arginine, and threonine. The broilers housed in tem peratures below 25.3 degrees C showed increased weight gains with incr eased CP diets, whereas birds housed in temperatures greater than 26.7 degrees C showed depressed gain with CP diets greater that 20%. Broil ers fed the 16 and 18% diets did not show increased gains with the fiv e added essential amino acids under any temperature conditions, indica ting that other amino acids were limiting.