Effect of pasture, confinement, and diet fortification with vitamin E and selenium on reproducing gilts and their progeny.

A total of 48 gilts were used to evaluate the effects of a corn-soybean meal diet with or without vitamin E and Se fed on pasture or in confinement. The effects of these treatments on gilt serum and tissue alpha-tocopherol and Se concentrations and those of their progeny at weaning (28 d) were evaluated. During gestation, the experiment was a 2 x 2 factorial arrangement of treatments in a split-plot design that compared the housing system (pasture or confinement) and the effect of diets fortified with or without vitamin E (22 IU/kg) and Se (.3 ppm). The lactation study was a 2 x 2 factorial arrangement of treatments in a split-plot design evaluating the two housing systems during gestation or lactation only when gilts were fed the unfortified basal diet. The gilts fed the vitamin E- and Se-supplemented diet remained either on pasture or in confinement during both reproductive phases and served as positive controls. Gilts were bled at breeding, at 30, 60, and 90 d postcoitum, at farrowing, and at weaning (28 d). Three pigs per litter were bled from all litters at weaning. Six pigs per treatment group were killed at weaning and livers were collected. Pasture lots contained orchardgrass, ryegrass, and alfalfa; different lots were used during each reproductive phase.(ABSTRACT TRUNCATED AT 250 WORDS)