Nitrogen balance and body weight change of adult roosters fed single essential amino acid devoid diets.

Diets completely devoid of single essential amino acid were fed to adult roosters for 7 days to investigate the effect on nitrogen balance and body weight change. Depending upon the kind of amino acid deprived from the diet the effects were different and the existence of the nutritional specificity of essential amino acid was confirmed. Among the essential amino acids tested, lysine, histidine and leucine had the least effect and threonine, arginine and methionine had the severest one. All other amino acids tested, tryptophan, glycine, phenylalanine and isoleucine, had medium effect of deficiency.