Selenium in poultry nutrition: a review

Selenium has been known for two centuries and its biological activities have been studied for nearly a hundred years, however the problem of Se deficit has still been persisting both in humans and animals. The cause of Se deficit in animals may be low Se level in soil. This mainly applies to cattle and sheep with their direct link to soil via roughage. The risk of Se deficit in pigs and poultry is lower due to lower dependence on soil Se level in the region and Se fortification in feed mixes. The present research focuses on the effects of Se on meat and egg quality, antioxidant activity of Se, effects on fatty acid levels, activity of glutathione-peroxidase, or the effect of Se on the immune system. Ensuring natural Se supply in human nutrition by food of animal origin, mainly poultry meat and eggs (the “functional foods”), is another area to which extensive attention has recently been paid.