Effect of Supplemental Selenomethionine on Growth Performance and Serum Antioxidant Status in Taihang Black Goats

Abstract

An experiment was conducted to evaluate the effect of different levels of supplemental selenomethionine (Se-Met) on growth performance and serum antioxidant status in Taihang Black goats. Fifty 16-week-old goats with an average body weight of 12.5±0.5 kg were randomly assigned to five treatments fed a basal diet (0.049 mg Se/kg DM) supplemented with 0 (control), 0.10, 0.30, 0.50 and 1.00 mg of Se/kg DM (form Se-Met) for 80 days. Average daily gain and feed efficiency were higher (p 0.05). Se-Met supplementation significantly increased (p<0.01) the activity of glutathione peroxidase enzymes (GSH-Px) and superoxide dismutase (SOD) in serum. The group supplemented with 0.50 mg Se/kg DM had the highest activity of GSH-Px compared with other groups (p<0.05). Serum SOD activity was higher (p<0.05) in goats supplemented with both 0.30 and 0.50 mg Se/kg DM than in control goats and goats supplemented with 1.00 mg Se/kg DM. Serum glutathione-S-transferase (GST) activity and malondialdehyde (MDA) concentration were significantly decreased (p<0.05) in goats supplemented with 0.30, 0.50 and 1.00 mg Se/kg DM compared with control values. These results indicated that Se-Met supplementation markedly improved the antioxidant status in goats. Blood Se concentration increased linearly (p<0.001) and quadratically (p<0.001) as the level of supplemental Se-Met increased. The concentration of Se in the control diet (0.049 mg Se/kg DM) did not satisfy the Se requirement in goats as indicated by reduced growth rate, feed efficiency, activities of GSH-Px and SOD in serum, and blood Se concentrations. In conclusion, it is recommended that 0.30 to 0.50 mg of Se/kg DM from Se-Met (total diet Se of 0.349 to 0.549 mg/kg DM) be supplied in the diet of Taihang Black goats to enhance growth performance and improve antioxidant status.