No abstract

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.

No abstract

A total of 72 pigs weaned at 4 wk of age were allotted by litter and weight to nine treatment groups and fed 20% protein cornsoybean meal diets supplemented with various levels of inorganic Se during a 37-d postweaning period. Eight groups were fed diets with 0, 2.5, 5.0, 7.5, 10, 15, 20 or 40 ppm Se provided as sodium selenite, while a ninth was offered the 0- and 40-ppm Se diets in separate feeders. Gains and feed intakes were similar during the trial for the 0- and 2.5-ppm Se diets. Both gain and feed intake declined as dietary Se levels above 5.0 ppm increased. At a dietary Se concentration of 40 ppm, feed consumption ceased within a few days of feeding and subsequent gains were negative. Pigs offered both the 0- and 40-ppm Se diets preferentially selected the basal as compared with the 40-ppm Se diet. When the feeders were switched at 28 d they refused the 40-ppm Se diet within a few hours. After a 17-d period, pigs fed the 20- or 40-ppm Se diet were not able to coordinate their walk, with many exhibiting an inability to stand. Alopecia was demonstrated in pigs fed 15 ppm Se or higher at 17 d, but was evident in the 5.0-ppm group at 37 d. At the termination of the trial, abnormal hoof formation at the coronary band was evident in pigs fed diets containing Se greater than or equal to 5 ppm.(ABSTRACT TRUNCATED AT 250 WORDS)