Metabolism of Sulfur-containing Amino Acids by Pregnant Merino Ewes

Abstract

The availability and utilization of cystine and methionine were measured in single-bearing Merino ewes on three occasions, approximately 90, 110 and 130 days after mating, and the effects on these traits of sulfur amino acids (SAA) infused into the abomasum were also measured. Two levels of SAA were infused containing 0·5 or 1·0 g day-i organic sulfur with DL-methionine contributing two-thirds and L-cystine onethird of the supplementary sulfur. The quantity of the diet offered was increased at each occasion so as to maintain maternal liveweight.