Synthesis of Cystine in Wool from Elemental Sulfur and Sulfate Sulfur

Synthesis of cystine in the sheep from elemental and sulfate sulfur has been shown using S35 as a tracer. Although the data obtained in this experiment are limited, the sulfur35 activity of the wool suggests that sulfate sulfur may be better utilized for the synthesis of cystine than is elemental sulfur. This may in part be due to the difference in solubility of the two compounds. The possible significance of the findings in relation to ruminant nutrition is briefly discussed.