Effect of dietary alpha-tocopheryl acetate on the uptake and distribution of alpha-tocopherol in turkey tissues and lipid stability

The effect of including all-rac-α-tocopheryl acetate [20 (E20), 300 (E300) and 600 (E600) mg/kg diet] in the diet of turkeys, for up to 21 weeks, on uptake and distribution of α-tocopherol and on the oxidative stability of tissues was investigated. Marked differences were observed in the concentrations of α-tocopherol in different tissues. Overall α-tocopherol levels responded to dietary intake in the order of gizzard > heart > lung ≈ spleen > liver > thigh muscle > abdominal fat > breast muscle > brain. After 5 weeks of supplementation with 300 mg α-tocopheryl acetate/kg, the α-tocopherol levels of both thigh [2.8 (s.d. 0.22) μg/g] and breast muscle [1.6 (s.d. 0.18) μg/g] were ∼3- to 6-fold higher than the basal levels in thigh and breast. In the case of breast muscle, only a small but insignificant increase in the α-tocopherol concentration was observed with further supplementation for up to 21 weeks. However, the levels of α-tocopherol in thigh muscle further increased significantly (P < 0.01) after 9 [3.7 (s.d. 0.18) μg/g] and 13 [4.5 (s.d. 0.28) μg/g] weeks of supplementation. The levels of α-tocopherol were significantly (P < 0.01) higher at all time points (except week 1) in both muscles from turkeys fed the E600 diet compared with those fed the E300 diet. In the E600 group, the α-tocopherol levels increased at an average weekly rate of 0.30 μg/g and 0.23 μg/g up to week 13 for thigh and breast, respectively. The stability of heart, breast and thigh muscle against iron/ascorbate-induced lipid peroxidation was significantly increased by α-tocopherol supplementation (300 or 600 mg/kg) for 21 weeks.