VITAMIN E NUTRITIONAL STATUS AND SERUM LIPID PATTERN IN NORMAL WEANLING RABBITS

In a 6-wk postweaning trial (Trial 1), 30 male New Zealand White rabbits were fed a starter diet with three different levels of all-rac-alpha-tocopheryl acetate (60, 160, or 260 mg/kg diet). Plasma concentrations of alpha-tocopherol and serum concentrations of total cholesterol, high density lipoprotein (HDL) cholesterol, and triglycerides were measured at 2, 4, and 6 wk. In a 20-wk postweaning trial (Trial 2), 48 male New Zealand White rabbits were divided into two groups; one group was fed a vitamin E-free diet, and the other was fed the same diet supplemented with 60 mg/kg of all-rac-alpha-tocopheryl acetate. Plasma concentrations of alpha-tocopherol and serum total cholesterol, HDL cholesterol, and triglycerides were measured at 2, 4, 6, and 20 wk. In Trial 1, split-plot ANOVA showed that dietary all-rac-alpha-tocopheryl acetate increased plasma alpha-tocopherol (P < .01); in addition, serum total cholesterol and triglycerides declined more rapidly (P < .01) and HDL cholesterol increased more rapidly (P < .005) in rabbits fed supplemental all-rac-alpha-tocopheryl acetate than in controls. The all-rac-alpha-tocopheryl acetate intake was significantly correlated with serum total cholesterol reduction and HDL cholesterol increase only when plasma alpha-tocopherol was relatively low (<23.5 mu mol/ L). In trial 2, the vitamin E-free diet caused an increase (P < .05) in total serum cholesterol and a reduction in HDL cholesterol (P < .05 at 6 wk and P < .01 at 20 wk). The overall results of this study suggest that vitamin E plays an important role in the regulation of serum concentrations of cholesterol and lipoproteins in weanling rabbits. Consequently, the maintenance of an adequate nutritional status of vitamin E in the postweaning period is important to avoid alterations of serum lipid pattern.