An evaluation of natural (RRR-α-tocopheryl acetate) and synthetic (all-rac-αlpha-tocopheryl acetate) vitamin E fortification i

Three experiments conducted with weanling pigs evaluated the effects of vitamin E added to the drinking water or diet on plasma and tissue αtocopherol concentrations. When natural or synthetic vitamin E was used, it was added at an IU-equivalent basis, but natural vitamin E was 73.5% (mg basis) of the synthetic vitamin E. Experiment 1 used 18-d-old weanling pigs (n = 120) in a 3 × 2 factorial arrangement of treatments in a randomized complete block design with 4 replicates. The first factor evaluated the dietary levels of natural vitamin E (RRR-α-tocopheryl acetate) added at 0, 50, or 300 IU/kg, whereas the second factor was the natural vitamin E added to the drinking water at 0 or 100 IU/L. Pigs were bled at periodic intervals, and 1 pig per pen was killed at the end of the 21-d trial and tissues (liver, heart, lung, and loin) were collected for α-tocopherol analysis. When vitamin E was not added to the diet or water, plasmaα-tocopherol declined over the 21-d period. Although there were some interactions (P < 0.01), tissue and plasma α-tocopherol concentrations increased linearly when vitamin E was added to the diet or water. Experiment 2 was a 3 × 2 factorial in a randomized complete block design with 4 replicates. A total of 96 pigs weaned at 18 d of age, with an initial BW of 6.2 kg, were fed a nonvitamin E fortified diet,