Selenium in Poultry Nutrition: Lessons from Research and Wild Nature Selen U Hranidbi Peradi: Pregled Rezultata Istraživanja U Hranidbi Peradi I Divljih Ptica

Chick embryo tissues contain a high proportion of highly polyunsaturated fatty acids in the lipid fraction and therefore need antioxidant defence (Surai, 1999). It is well accepted that maternal diet composition is a major determinant of antioxidant system development during embryogenesis and in early postnatal development. The antioxidant system of the newly hatched chick includes the fat-soluble antioxidants, vitamin E and carotenoids, watersoluble antioxidants ascorbic acid and glutathione as well as antioxidant enzymes SOD, GSH-Px, catalase and selenium (Surai, 2002). Vitamin E and carotenoids are transferred from feed into egg yolk and further to embryonic tissues. Selenium content of the egg also depends on its concentration in the hen's diet, and also on the form of dietary Se used, since organic Se is more efficiently deposited in the egg yolk (Surai, 2006).