Effects of dietary vitamin D3 supplementation on growth performance, blood vitamin D status, and antioxidant capacity in weaning pigs.

Abstract

Objective: This study evaluated the effects of dietary vitamin D3 (VD₃) supplementation on growth performance, blood vitamin D, and antioxidant status in weaning pigs.

Methods: Forty newly weaned piglets (6.02 ± 1.17 kg) were assigned to two treatments with five replicates over a 28-d period. Treatments were 1) NRC-VD3: NRC recommended levels [220 IU/kg in Phase 1 (d 0-14 postweaning) and 200 IU/kg in Phase 2 (d 14-28 postweaning)], and 2) High-VD₃: a high level of VD3 (2,000 IU/kg in Phase 1 and 2). Body weight, average daily gain, average daily feed intake and gain-to-feed ratio were measured weekly. Blood samples were collected at d 14 and 28 postweaning for the analyses of plasma 25-hydroxycholecalciferol (25-OHD₃), total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) levels. Pearson correlation coefficients between plasma 25-OHD₃ and SOD, MDA, or T-AOC were determined.

Results: Growth performance did not differ in overall nursery period although feed intake was lower in the High-VD₃ group than the NRC-VD3 group in d 14-28 postweaning (p<0.05). Pigs fed High-VD₃ diets showed greater plasma 25-OHD₃ at d 14 and 28 postweaning (p<0.05), tended to have reduced plasma MDA (p = 0.06), and increased plasma SOD activity (p = 0.10) at d 14 postweaning compared with those fed NRC-VD3 diets with no effect in plasma T-AOC. At d 14 postweaning, plasma 25-OHD3 was positively correlated with plasma SOD activity (r = 0.532; p<0.05) and tended to be negatively correlated with plasma MDA levels (r = -0.491; p = 0.06).

Conclusion: High VD₃ supplementation at 2,000 IU/kg did not enhance growth performance, while improving plasma vitamin D and antioxidant status in weaning pigs compared to NRC-level supplementation. Therefore, supplementing weaning pigs with higher-than-recommended levels of VD₃ could be beneficial to enhance their antioxidant status and overall health.