Dietary 25(OH)D(3) supplementation to gestating and lactating sows and their progeny affects growth performance, carcass characteristics, blood profiles and myogenic regulatory factor-related gene expression in wean-finish pigs

OBJECTIVE: This experiment investigated the effects of supplementing vitamin D(3)-fortified sow and progeny diets with 25(OH)D(3) on growth performance, carcass characteristics, immunity, and pork meat quality. METHODS: The present study involved the assessment of supplementing the diet of sows and their progeny with or without 25 (OH)D(3) in a 2×2 factorial arrangement on the performance and production characteristics of wean-finish pigs. Forty-eight multiparous sows were assigned to a basal diet containing 2000 IU/kg vitamin D(3) and supplemented without (CON) or with (TRT) 50 μg/kg 25 (OH)D(3). At weaning, a total of 80 pigs each from CON and TRT sows were allocated to weaning and growing-finishing basal diets fortified with 2,500 and 1,750 IU/kg vitamin D(3) respectively and supplemented without or with 50 μg/kg 25(OH)D(3). RESULTS: Sows fed 25(OH)D(3)-supplemented diets improved pre-weaning growth rate of nursing piglets. A significant sow and pig weaning diet effect was observed for growth rate and feed efficiency (p<0.05) during days 1 to 42 post-weaning. Pigs consuming 25(OH)D(3)-supplemented diets gained weight faster (p = 0.016), ate more (p = 0.044) and tended to convert feed to gain more efficiently (p = 0.088) than those fed CON diet between days 98 and 140 post-weaning. Supplemental 25(OH)D(3) improved water holding capacity and reduced drip loss of pork meat, increased serum 25(OH)D(3) level, produced higher interleukin-1 and lower interleukin-6 concentrations in blood circulation, downregulated myostatin (MSTN) and upregulated myogenic differentiation (MYOD) and myogenic factor 5 (MYF5) gene expressions (p<0.05). CONCLUSION: Supplementing vitamin D(3)-fortified sow and wean-finish pig diets with 50 μg/kg 25(OH)D(3) significantly improved production performance suggesting their current dietary vitamin D(3) levels are insufficient. In fulfilling the total need for vitamin D, it is strongly recommended to add 50 μg/kg 25(OH)D(3) “on top” to practical vitamin D(3)-fortified sow and wean-finish pig diets deployed under commercial conditions.