0
Vitamin D plays an essential role in maintaining proper Ca and P homeostasis within the body of mammals. Because most swine production occurs in environmentally controlled facilities, direct sunlight is no longer a source of vitamin D for the neonatal pig, which could impact bone growth and muscle function. Previous studies indicated that pigs have lower than expected concentrations of vitamin D at weaning which may be the responsible of inadequate bone mineralization and microfractures development. Therefore, the aim of this study was to determine the effects of oral vitamin D3 supplementation on growth performance, serum 25(OH)D3 concentrations, and bone mineralization of pre- and postweaning pigs. A total of 270 pigs from 29 litters (initially 2 d of age) were used in a 52-d study. Experimental treatments consisted of 3 oral dosage treatments: (1) control (1 mL peanut oil), (2) 40,000 IU vitamin D3 delivered in 1 mL peanut oil, or (3) 80,000 IU vitamin D3 delivered in 1 mL peanut oil. Pigs were initially weighed over 2 different days (d 0 or 2), allowing pigs to be placed on test 1 or 2 d after birth. Within a litter, pigs were assigned to similar-weight matched sets of 3 and were allotted to 1 of the 3 oral dosage treatments. Blood samples were collected from pigs of 29 matched sets (87 pigs total) prior to dosing, then the same matched set pigs were bled periodically throughout the trial to measure 25(OH)D3 serum concentrations. All pigs were weighed again on d 10 and 20. On d 20, pigs were weaned and allotted to the nursery portion of the trial and all pigs were fed common diets from d 20 to 52 of age. Pigs were also randomly selected for necropsy on d 19 and d 35. Eighteen pigs were necropsied on d 19 (6 matched sets for a total of 6 pigs per treatment) and 12 pigs were necropsied on d 35 (6 control pigs and 6 pigs previously dosed with 80,000 IU vitamin D3). Bone and tissue samples were collected. All bone samples were analyzed for ash content and histopathology.
Increasing oral vitamin D3 increased serum 25(OH)D3 concentrations on d 10 and 20 (quadratic, P < 0.01), and on d 30 (linear, P < 0.01). During lactation, no differences were observed in ADG across treatments, but at weaning, pigs previously dosed with vitamin D3 were 0.14 kg heavier than control pigs. Throughout the nursery study (d 20 to 52), no significant differences were observed in ADG, ADFI, or F/G; however, on d 52, pigs previously dosed with vitamin D3 were 0.22 kg heavier than control pigs. Vitamin D3 supplementation had no effect on bone ash concentration of either the femur. Pathologic lesions were not identified by microscopic evaluation of bone, regardless of vitamin D3 treatment.
Oral vitamin D3 did not influence growth performance or bone measurements in this study, but more research may be needed to test the response under field conditions with more health challenges.
JR Flohr, MD Tokach, SS Dritz, SC Henry, ML Potter, LM Tokach, JP Goff, RL Horst, JC Nietfeld, DM Madson, SM Ensley, RD Goodband, JL Nelssen, JR Bergstrom and JM DeRouchey. The effects of orally supplemented vitamin D3 on serum 25(OH)D3 concentrations and growth of pre-weaning and nursery pigs. Swine Day, Kansas State University, 34-45.
