Partial cholecalciferol replacement with 1,25-dihydroxycholecalciferol glycoside in diets for piglets

Context Vitamin D supplementation plays a key role because its actions positively affect the animal's overall health for optimal performance. Aims To assess partial cholecalciferol replacement with 1,25-dihydroxycholecalciferol glycoside for piglets on nutrient digestibility and daily balance of calcium and phosphorus, growth performance and blood metabolites. Methods To test digestibility, a total of 36 whole male piglets (18.79 +/- 3.37 kg BW) were assigned in a randomised complete block design, with four treatments: (1) D-3 (100% of the vitamin D supplemented with 1969 IU of cholecalciferol), (2) no supplemental sources of vitamin D (control), (3) D-3 (50% of requirement + 0.375 mu g of 1,25(OH)(2)D-3 glycoside) or (4) 100% supplemented with 0.750 mu g of 1,25(OH)(2)D-3 glycoside. Nine replicates were performed, with one animal per experimental unit. For growth performance (Experiment II), a total of 128 whole male piglets (6.82 +/- 0.38 kg BW) were distributed in a randomised complete block design, with four treatments: (1) 100% D-3 (2707 IU in the pre-starter phase I, 2405 IU in the pre-starter phase II and 1969 IU in the starter phase), (2) 50% D-3 + 0.25 mu g of 1,25(OH)(2)D-3 glycoside, (3) 25% D-3 + 0.375 mu g of 1,25(OH)(2)D-3 glycoside or (4) 100% supplemented with 0.50 mu g of 1,25(OH)(2)D-3 glycoside. Eight replicates were conducted, with and four animals per experimental unit. Key results The apparent digestibility of nutrients and mineral balance were not influenced (P > 0.1). The results of Experiment II indicate effects (P < 0.1) of vitamin D supplementation on the growth performance evaluated during the nursery phase. Plasma calcium concentrations in the pre-starter II phase showed (P < 0.1) the highest concentration in the 50/50 treatment. Alkaline phosphatase showed (P < 0.001) a difference between treatments in the starter phase, with treatment 25/75 promoting the lowest plasma value. Conclusions Cholecalciferol or 1,25-dihydroxycholecalciferol glycoside resulted in similar digestibility and balance of calcium and phosphorus, even though the combination increased plasma calcium and alkaline phosphatase concentration in piglets. In addition, the partial replacement reduced the voluntary feed intake of piglets during nursery phase. Implications This investigation provided new information on partial cholecalciferol replacement with 1,25-dihydroxycholecalciferol glycoside in piglet starter as an alternative in post-weaning nutrition.