On the Amino Acids Essential for the Tissues of the Sheep

Abstract

A lactating ewe was injected intravenously with sodium [l. 14C]acetate and samples of the wool and milk produced subsequently were collected. Some of the casein from the milk produced 1-3 hr after the injection was hydrolysed and the distribution of 14C among most of the amino acids determined. The results showed that only the following amino acids became labelled: glutamic acid, aspartic acid, proline, alanine, arginine, and serine. By analogy with earlier work on cows by Black et al. (1957) it was concluded that these amino acids are also non� essential for the tissues of the sheep.