Effects of supplemental selenium on swine. II. Growing-finishing.

The effects of dietary selenium (Se), copper (Cu) and zinc (Zn) on growth characteristics, selected blood parameters and carcass traits in growing-finishing swine were evaluated in two experiments. In the first experiment, 48 Duroc barrows and gilts weighing approximately 30 kg were al lot ted by sex and weight to six dietary treatments. They were fed a basal 16% crude protein diet containing .08 ppm Se, 12.5 ppm Cu and 82 ppm Zn alone or supplemented with: .1 ppm Se; 125 ppm Cu; 80 ppm Zn; .1 ppm Se plus 125 ppm Cu;or .1 ppm Se plus 80 ppm Zn. Blood samples obtained from each animal at 100 kg live weight revealed no significant t reatment differences for RBC 7 s Se uptake, plasma Se, Cu and Zn, whole blood Se, or hematocrit , although plasma Se tended to be higher in the Se supplemented pigs. In the second experiment, 72 Duroc barrows and gilts from sows fed two levels of Se (.1 and .2 ppm Se) were al lot ted to treatments as in experiment 1. Upon reaching 100 kg, the pigs were slaughtered and blood and carcass data collected. The Se content of the longissimus muscle taken at the last rib was increased by the addition of Se to either the sow diet (P<.05) or the growing-finishing diet (P<.001). Plasma Se was increased (P<.05) by additional Se in the growing-finishing diet, but was not significantly affected by dietary Se levels fed the sow. Average daily gain and longissimus muscle dry matter were significantly increased in pigs fed additional Zn. Feed efficiency was not significantly affected by treatment. (