Methionine supplementation of milk proteins for preruminant lambs. II.* Effect on wool growth, liveweight gain and body composition

Abstract

Twenty-six crossbred lambs in two equal groups, aged 2-5 days, were given a low protein diet based on cows' milk, with or without a supplement of DL-methionine, for an experimental period of 21 days. Intake of gross energy ranged from 518 to 1276 kJ/day per kg0.73 Nitrogen and sulphur retentions were estimated by balance methods and nitrogen retention was also ascertained by comparative slaughter. In the group supplemented with methionine the apparent digestibility of sulphur increased significantly, but there were no significant differences between the groups in the apparent digestibilities of dry matter and nitrogen or in gross energy. Retention of nitrogen and sulphur in the body tissues and in the wool increased significantly. There was a significant increase in wool growth and in the sulphur content of wool, but not in the nitrogen content. Methionine supplementation had no significant effect on liveweight gain. The gain in empty liveweight of the supplemented lambs comprised significantly more protein and significantly less fat than that of the unsupplemented lambs. *Part I, Aust. J. Agric. Res. 26: 673 (1975)