Metabolic Fate of S35 in the Lactating Cow When Fed S35O2 Preserved Silage

Abstract
The metabolic fate of S35 from 3 lots of grass preserved with S35O2 was studied with lactating dairy cows. Most of the S added to the forage in the form of SO2 remained in a water soluble form. Approx. 2/3 of the ingested S35 was absorbed and then eliminated in the urine and 1/3 was eliminated in the feces. Small amts. of the absorbed S35 was synthesized into the proteins of the milk and of the blood. This indicates that sulfur from SO2 used as a silage preservative may be of value nutritionally.