Dietary 25‐hydroxycholecalciferol supplementation improves performance, immunity, antioxidant status, intestinal morphology, and bone quality in weaned piglets

BACKGROUND 25‐Hydroxycholecalciferol (25OHD 3 ) is a new feed additive, which is a potential alternative to vitamin D 3 in swine nutrition. The objective of this study was to determine the effects of different doses of 25OHD 3 supplementation on performance, immunity, antioxidant capacity, intestinal morphology and bone quality in piglets. RESULTS As dietary 25OHD 3 supplementation increased, the average daily gain (ADG) improved ( P  < 0.05) quadratically during days 1–14, and tended to increase ( P = 0.06) quadratically during the overall period of the experiment. Increasing 25OHD 3 supplementation increased (linear effect, P  < 0.05) the serum 25OHD 3 level and serum glutathione peroxidase (GSH‐Px) activity. On day 14, serum immunoglobulin A (IgA) was increased (linear and quadratic effects, P  < 0.05) as dietary 25OHD 3 supplementation increased. On day 28, serum IgA level was higher ( P  < 0.05) linearly and the complement 3 (C3) level was reduced ( P  < 0.05) linearly as dietary supplementation of 25OHD 3 increased. The mucosal GSH‐Px activity of the small intestine was higher (quadratic effect, P  < 0.05) with increasing 25OHD 3 supplementation. Jejunal villus height ( P = 0.06) and villus height to crypt depth ratio ( P = 0.07) tended to increase quadratically, and the villus height to crypt‐depth ratio of the ileum increased ( P  < 0.05) linearly and quadratically with increasing 25OHD 3 supplementation. Dietary supplementation with an increasing level of 25OHD 3 increased breaking strength of tibias and femurs (quadratic effect, P  < 0.05). CONCLUSION Increasing dietary 25OHD 3 supplementation partly improved performance, immunity, antioxidant status, intestinal morphology, and bone properties of weaned piglets. © 2020 Society of Chemical Industry