Effect of dietary and injectable vitamin E and selenium in weanling swine antigenically challenged with sheep red blood cells.

Two experiments were conducted to evaluate the effect of supplemental vitamin E and (or) Se, provided either in the diet or by injection, on humoral antibody production in weanling swine after an antigenic challenge with sheep red blood cells (SRBC). In the first experiment, a 2 x 2 factorial design was used, with pigs fed either 0 or .5 ppm Se and 0 or 220 IU vitamin E/kg diet. The basal diet contained a natural Se and alpha-tocopherol content of .02 ppm and 7 mg/kg, respectively. In a second 2 x 2 factorial trial, 0 or 6 mg Se and 0 or 220 mg alpha-tocopherol were injected intramuscularly into weaning pigs fed the basal diet without supplemental Se or vitamin E. A fifth treatment group was fed a positive control diet containing both nutrients (.5 ppm Se and 220 IU vitamin E/kg). In both experiments, intraperitoneal injections of SRBS (1 x 10(8)) were administered weekly, with hemagglutination titers determined at these intervals. Hemagglutination assays indicated that vitamin E and Se independently enhanced the immune response, particularly during the latter weeks of the experiment. The combination of both nutrients, provided either in the diet or via injection, resulted in a further increase in hemagglutination titers, suggesting an additive response. Pigs receiving either Se or vitamin E had higher serum concentrations of the nutrient provided. Dietary sources of these nutrients resulted in greater serum and tissue levels than did injections.