Identification of [75se]Selenomethionine in Ewe Milk Protein Following the Intraruminal Administration of Na75seo3 as a Single Oral Dose

Abstract

Inorganic selenium, as Na275Se03, was given intraruminally to lactating ewes, and for 48 hr afterwards samples of blood and milk were taken regularly. The animals were then slaughtered and tissues taken for further analysis. Evidence is presented, based on isolation techniques using Sephadex chromatography and gas-liquid chromatography, that 75Se is incorporated into milk proteins as selenomethionine_ It is estimated that at least 3% of the selenium that enters the milk, from this inorganic source, is present as bound selenomethionine. This is a minimal value, since it has been shown that selenomethionine is easily degraded during a number of the isolation procedures.