Equivalence of Methionine Hydroxy Analog and Methionine for Chickens Fed Low-Protein Diets

Abstract

WHEN chicks are fed methionine-deficient diets containing at least 20% protein, the growth response obtained by supplementation with methionine hydroxy analog (MHA)1 is equivalent to that obtained from dl-methionine (Bird, 1952; Gordon et al., 1954) even when compared on a weight for weight basis (Gordon and Sizer, 1955). Sullivan and Bird (1957) however, have reported that MHA as a supplement to diets containing only 12 to 14% protein failed to support growth equivalent to dl-methionine, unless nitrogen from diammonium citrate (DAC) or urea was added to these diets. In the experiments presented we have found that even with a low protein level the growth response to MHA and dl-methionine were equivalent.EXPERIMENTALExcept where indicated, day-old New Hampshire cockerels obtained from a commercial hatchery were used throughout. They were divided into groups of 20 birds each. The chicks were reared in wire-floored electrically heated batteries in an air-conditioned room. Feed …