Influence of environmental temperature on protein and amino acid needs of poultry

Poultry production generally declines during adverse hot weather conditions. Dietary adjustments are often made to attempt to overcome the reduced performance, with an increase in dietary protein or amino acids being common. A review of the literature regarding the influence of environmental temperature on the amino acid needs of the chicken does not support an increase in the amino acid needs at temperature in excess of 32 C. Studies with broilers, growing pullets, and laying hens are in agreement that increased amino acid levels cannot effectively compensate for the reduced feed intake frequently observed at the higher envirnomental temperatures. Excessive dietary amino acid levels contribute to inhibition of feed intake and reduction in growth rate. Studies with practical-type diets have indicated that the performance of broiler chicks under conditions of high environmental temperatures may be improved through minimizing the excess levels of amino acids in the diet. This may be accomplished by means of blending protein sources combined with supplementation with commercially synthesized amino acids.