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-alpha-tocopheryl acetate [20 (E20), 30 0 (E300) and 600 (E600) mg/kg diet] in the diet of turkeys, for up to 21 weeks, on uptake and distribution of alpha-tocopherol and on the ox idative stability of tissues was investigated. Marked differences were observed in the concentrations of alpha-tocopherol in different tissu es. Overall alpha-tocopherol levels responded to dietary intake in the order of gizzard > heart > lung approximate to spleen > liver > thigh muscle > abdominal fat > breast muscle > brain. After 5 weeks of supp lementation with 300 mg alpha-tocopheryl acetate/kg, the alpha-tocophe rol levels of both thigh [2.8 (s.d. 0.22) mu g/g] and breast muscle [1 .6 (s.d. 0.18) mu g/g] were similar to 3- to 6-fold higher than the ba sal levels in thigh and breast, In the case of breast muscle, only a s mall but insignificant increase in the alpha-tocopherol concentration was observed with further supplementation for up to 21 weeks. However, the levels of alpha-tocopherol in thigh muscle further increased sign ificantly (P < 0.01) after 9 [3.7 (s.d. 0.18) mu g/g] and 13 [4.5 (s.d . 0.28) mu g/g] weeks of supplementation. The levels of alpha-tocopher ol were significantly (P < 0.01) higher at all time points (except wee k 1) in both muscles from turkeys fed the E600 diet compared with thos e fed the E300 diet, In the E600 group, the alpha-tocopherol levels in creased at an average weekly rate of 0.30 mu g/g and 0.23 mu g/g up to week 13 for thigh and breast, respectively. The stability of heart, b reast and thigh muscle against iron/ascorbate-induced lipid peroxidati on was significantly increased by alpha-tocopherol supplementation (30 0 or 600 mg/kg) for 21 weeks.