NUTRITIONAL SIGNIFICANCE OF SELENIUM SUPPLEMENTATION IN A SEMI-PURIFIED DIET FED DURING GESTATION AND LACTATION TO FIRST-LITTER GILTS AND THEIR PIGLETS

Twelve purebred Landrace pregnant gilts were introduced to the experimental diets in pairs (littermates) in order to study the nutritional significance of 0.1 ppm Se supplementation (+Se) during gestation and lactation in a semi-purified diet containing adequate amounts of vitamin E but low in Se (0.018 ppm; −Se). Gilts were fed 2 kg/day during gestation and ad libitum during a 3-wk lactation. Animal response was evaluated in terms of reproductive performance, blood, colostrum and milk parameters. Litter size and total litter weight at birth and at weaning were not affected by the Se levels fed to the dams. Mortality rates at birth were 1.61 and 13.64% and from birth to weaning were 18.09 and 5.26% for +Se and −Se litters, respectively. A continuous decrease of blood Se content was observed in gilts throughout gestation, being significantly lower for the −Se group compared to the +Se group. Plasma glutathione peroxidase (GSH-Px) activity followed the same pattern observed in blood Se content. Content of Se in colostrum, although always higher than in milk, was significantly lower in the −Se gilts than the +Se group. Blood Se from piglets of the +Se gilts was significantly higher than the blood of piglets from litters of the −Se gilts at birth, and during the 3-wk lactation. Levels of GSH-Px activity in the plasma of piglets from litters of the two experimental groups of gilts were similar at birth, but by 3 wk lactation piglets from +Se gilts showed significantly greater GSH-Px activity than piglets from −Se gilts. Growth rate of the piglets at 4 wk postweaning was significantly affected by the dietary Se intake of their mothers during gestation and lactation. However, no differences in growth rate were observed among littermates that received a starter diet with or without Se supplementation. Key words: Selenium, gilts, pregnancy, lactation, piglets, postweaning