Dietary Supplementation of 25-Hydroxyvitamin D(3) Improves Growth Performance, Antioxidant Capacity and Immune Function in Weaned Piglets

This study was conducted to evaluate the effects of 25-hydroxyvitamin D(3) (25(OH)VD(3)) and Vitamin D(3) (VD(3)) supplemented in the diet of weaned piglets on their growth performance, bone quality, intestinal integrity, immune function and antioxidant capacity. A total of 192 weaned piglets were allocated into four groups and they were fed a control diet containing 2000 IU VD(3) (negative control, NC), NC + 100 ppm colistin sulfate (positive control, PC), NC + 2000 IU VD(3) (VD(3)) and NC + 2000 IU 25(OH)VD(3) (25(OH)VD(3))(.) The results showed that 25(OH)VD(3) improved the growth performance, bone quality and antioxidase activity of piglets compared with the other groups. Meanwhile, 25(OH)VD(3) up-regulated ileal mRNA expressions of tight junction proteins and host defense peptides. The VD(3) group had an increased intestinal sIgA content and mRNA expression of pBD-1 compared with the NC group. Both groups of VD(3) and 25(OH)VD(3) altered the microbial β-diversity compared with the NC group, and 25(OH)VD(3) increased ileal concentrations of acetate and butyrate. In conclusion, our findings indicated that a regular dosage of 2000 IU VD(3) in the weaned piglets’ diet did not achieve optimal antioxidant capacity and immune function. 25(OH)VD(3) had better growth performance than VD(3) at the same inclusion level, which is associated with the improved intestinal integrity and antioxidant capacity.