Abstract
Nano-elemental selenium (nano-Se) has attracted more attention than sodium selenite (SS), owing to its low toxicity, high bioavailability, strong adsorbing ability and high catalytic efficiency. The purpose of the present study was to examine the effects of dietary supplementation with SS and nano-Se on the growth performance, digestibility, blood parameters and gene expressions related to growth and oxidation in broilers. Thirty broiler chicks at 15 days old were randomly divided into three dietary treatments, namely control (basal diet without any supplementation with selenium (Se)); SS treatment (basal diet + 1 mg SS/kg diet); and nano-Se treatment (basal diet + 0.5 mg nano-Se/kg diet). The birds were given the experimental diets from 15 to 27 days old. Bodyweight gain was enhanced in the nano-Se group, but was not influenced by SS supplementation. Breast muscle and thigh muscle weights were higher in dietary supplementation of nano-Se. Although muscle fat and Se content were significantly higher in dietary supplementation of SS and nano-Se in comparison with control, muscle thiobarbituric acid reactive substance (TBARS) and a-tocopherol concentrations were not influenced. Moreover, by feeding SS or nano-Se, glutathione peroxidase (GPx) and superoxide dismutase (SOD) mRNA expressions in muscles were higher than in the control group. Plasma total cholesterol and triglyceride concentrations were significantly lower in the nano-Se group than in the other groups, while, plasma high-density lipoprotein (HDL) cholesterol, serum aspartate aminotransferase (AST) and triiodothyronine (T-3) were not significantly affected. However, mRNAs levels in muscle tissue, namely insulin-like growth factor-I (IGF-I), insulin receptor (IR) and glucose transporters (Glut-8) were significantly higher; while atrogin-1 was not significantly affected by dietary Se supplementation. It could be concluded that dietary SS and nano-Se might be involved in improving growth performance, muscle Se content and antioxidative properties in broilers.