Effects of dietary 25-hydroxyvitamin D3 supplementation on growth performance, immune function and antioxidative capacity in weaned piglets.

The study evaluated the effects of different doses of 25-hydroxyvitamin D3 (25(OH)D3) on growth performance, immune function and antioxidative capacity in piglets. In a 21-d trial, 35 weaned pigs were divided into five groups and diets were supplemented with 5.5 (control), 43.0, 80.5, 118.0 and 155.5 μg 25(OH)D3/kg, respectively. No treatment effects were observed for average daily gain, average daily feed intake and feed to gain ratio. Increasing dietary 25(OH)D3 levels increased serum 25(OH)D3 concentrations linearly (p < 0.01), decreased the frequency of CD3+CD4+ and CD3+CD8+ T cells (p < 0.01), and the serum level of complement component 3 (p < 0.05). Supplementation of 80.5 and 118.0 μg 25(OH)D3/kg enhanced the activity of serum glutathione peroxidase (p < 0.05) and addition of 43.0 μg 25(OH)D3/kg increased the malondialdehyde concentration (p < 0.05). Overall, feeding high-dose 25(OH)D3 to weaned pigs partly improved immune functions and the antioxidative capacity.