Bioefficiencies of α-, γ- and δ-tocopherol in comparison with all-rac-α-tocopherol were established in broiler chickens. For this, 1-d-old male broiler chickens received a diet deficient in vitamin E and supplemented with increasing doses of the corresponding tocopheryl acetates. After 2 and 3 weeks of feeding, the animals were killed to obtain blood and liver samples. The ex vivo tests used were detergent induced haemolysis and pentane production by liver microsomes. Bioefficiencies were calculated by comparison of the dose–response curves. It is concluded that haemolysis and pentane production are appropriate indicators of the bioefficiency of tocopherols in broiler chickens. The values obtained by both tests hardly differed and agree well with the figures previously obtained from rats and other species.
