Efficacy of dietary vitamin D3 and 25(OH)D3 on reproductive capacities, growth performance, immunity and bone development in pigs.

Vitamin D₃ (Vit D₃) and 25(OH)D₃ are used as dietary sources of active vitamin D (1,25(OH)₂D₃) in pig husbandry. Although acting primarily on intestine, kidney and bone, their use in pig nutrition has shown a wide range of effects also in peripheral tissues. However, there is an ambiguity in the existing literature about whether the effects of Vit D₃ and 25(OH)D₃ differ in attributing the molecular and phenotypic outcomes in pigs. We searched Web of Science and PubMed databases concerning the efficacy of Vit D₃ in comparison with 25(OH)D₃ on pig physiology, i.e. reproductive capacities, growth performance, immunity and bone development. Dietary intake of Vit D₃ or 25(OH)D₃ did not influence the reproductive capacity of sows. Unlike Vit D₃, the maternal intake of 25(OH)D₃ significantly improved the growth performance of piglets, which might be attributed to maternally induced micronutrient efficiency. Consequently, even in the absence of maternal vitamin D supplementation, 25(OH)D₃-fed offspring also demonstrated better growth than the offspring received Vit D₃. Moreover, a similar superior impact of 25(OH)D₃ was seen with respect to serum markers of innate and humoral immunity. Last but not least, supplements containing 25(OH)D₃ were found to be more effective than Vit D₃ to improve bone mineralisation and formation, especially in pigs receiving basal diets low in Ca and phosphorus. The insights are of particular value in determining the principal dietary source of vitamin D to achieve its optimum utilisation efficiency, nutritional benefits and therapeutic potency and to further improve animal welfare across different management types. [ABSTRACT FROM AUTHOR]