Expert interview: Selenium-enriched yeast

Selenium-enriched yeast (also called selenized yeast) was the first organic selenium (Se) source used in animal nutrition. It is an inactivated yeast enriched in selenium. Specifically selected yeast strains can utilize inorganic selenium and incorporate it into the yeast biomass in the form of organic selenium compounds such as selenomethionine and selenocysteine. Producing high-quality, concentrated, Se-enriched yeast is the fruit of proper yeast strain selection and specific process development.

All selenized yeast available in the market are produced with a specific yeast strain. Due to the difference in DNA, each selenized yeast will bring its own profile, which lead to differences in the exact composition of organic selenium compounds.

Additionally, the mastering of the production process is what makes the difference. Fermentation conditions, proper washing of the yeast biomass and a gentle drying process can optimize bioavailability in the animal. Finally, quality control of each batch produced is crucial to ensure a safe and consistent feed additive.

Selenium contributes to several important functions in the body, such as prevention of oxidative stress, proper thyroid function, immunity and reproduction. Selenium is beneficial for all animal species — from farm animals to companion animals or aquatic species. It is also essential for humans!

Additionally, organic selenium brings benefits that are unique compared to inorganic selenium. Selenomethionine is incorporated into proteins in place of methionine. The selenized proteins will then be found in muscles, milk or eggs. Having selenomethionine stored in the muscles also helps during stressful conditions when catabolism is happening, as this selenium can be released and used to produce functional seleno-enzymes for antioxidant support and more! Another benefit is selenium transfer to the young animals through eggs or colostrum.