Effects of selenium supplementation on selenium status of farmed fallow deer in outdoor pens

The study investigated the effects of selenium (Se) supplementation on Se status in farmed fallow deer. Fallow deer were housed on grass pasture and adapted to consume ～200 g of pelleted grain daily. Animals were divided into two groups. One group received pelleted grain enriched with sodium selenate for 12 weeks (Se+ group, N = 10). Se intake for the first 7 weeks was 0.18 mg/kg dry matter (DM) and 0.32 mg/kg DM for the subsequent 5 weeks. The control group was fed pelleted grain without extra Se (Se? group, N = 9, 0.06-0.08 mg/kg DM). Blood samples were collected at the beginning and the end of the experiment. After the animals were slaughtered, tissue samples were collected for analysis of Se concentrations and Se-dependent glutathione peroxidase 1 (GPx1) activity. In addition, Se-independent α-glutathione-S-transferase (α-GST) activity was analyzed in liver tissue. Se supplementation significantly increased Se levels in plasma and in tissues as follows: liver > spleen > skeletal muscle > myocardium > kidney. Se supplementation also significantly increased GPx1 activity in tissues in the following order: liver > skeletal muscle > spleen = myocardium > kidneys. However, hepatic α-GST activity did not differ between Se+ and Se? groups. As expected, Se supplementation increased blood and tissue Se concentrations and GPx1 activity, which suggests a better antioxidant status. However, the activity of α-GST, an important Se-independent antioxidant enzyme, was not altered, presumably because GPx provided an adequate antioxidant capacity even though Se intake was low.