Effects of Nano-selenium Poisoning on Immune Function in the Wumeng Semi-fine Wool Sheep

The Wumeng semi-fine wool sheep is vital to the production system in Southwest China. To study the effects of nano-selenium (Nano-Se) poisoning in the Wumeng semi-fine wool sheep, poisoning model was established. A total of 20 animals with an average initial body weight (BW) of 35.57 ± 3.31 kg were used in this study. After 1-week-long acclimatization period, all animals were randomly divided into two groups: (1) control, with no any treatment; (2) Nano-Se group, orally administered 5 mg Nano-Se (BW/kg/day). There were 10 replications/group and one sheep/replication. The experiment lasted for 30 days. Compared with the control, hemoglobin, erythrocyte count, and packed cell volume in Nano-Se group markedly decreased (P < 0.01), and the activities of serum lactate dehydrogenase, glutamic oxaloacetic transaminase, cereal third transaminase, and alkaline phosphatase in Nano-Se group significantly increased (P < 0.01). T₃ and FT₃ in serum in Nano-Se group were greatly lower than those in the control (P < 0.01). Contents of T₄, FT₄, and TSH in serum in Nano-Se group were extremely higher than those in the control (P < 0.01). Levels of IgG, IgM, IgA, interleukin 2 (IL-2), and tumor necrosis factor-alpha (TNF-α) in Nano-Se group were much lower than those of the control (P < 0.01), but levels of interleukin 6 (IL-6) and interleukin-1β (IL-1β) were greatly higher than those in the control (P < 0.01). Compared with the control, serum superoxide dismutase, glutathione peroxide, total antioxidant capacity, and catalase from Nano-Se group extremely decreased (P < 0.01), and content of serum malondialdehyde in Nano-Se group markedly increased (P < 0.01). The current results indicated that the blood parameters in the Wumeng semi-fine wool sheep were affected by Nano-Se poisoning, and the immune function and antioxidant capacity were greatly reduced too.