Methionine supplements in chicken diets. II. A breed difference in growth response to DL-methionine

Abstract

In four experiments, White Leghorn chickens showed a highly significantly (P < 0.01) greater response in early growth following addition of DL-methionine to a practical basal diet, than Australorp chickens. Average increases in body weight were: White Leghorns, 10.95 per cent.; Australorps, 2.0 per cent. In crosses between these breeds, it was shown that the difference between the breeds can be explained by a single sex-linked gene or group of genes, dominant in White Leghorns. Possible biochemical bases for the breed difference are discussed.