Supplementing sows with a combination of vitamin D3 and 25(OH)D3, effects on dam and progeny vitamin D status and muscle fiber morphometrics

25-hydroxyvitamin D₃ (25(OH)D₃) has been suggested to have a higher bio-potency than vitamin D₃, enhancing calcium and phosphate absorption and also regulating immune functions. The major role vitamin D₃ plays is important for the growth and maintenance of a functional skeleton to sustain health and improve welfare and longevity. The aim of the present study was to determine if feeding a combination of vitamin D₃ and 25(OH)D₃ influenced neonatal and sow vitamin D status, muscle fiber morphometrics at birth and weaning, and subsequent growth performance. For that purpose, a total of 69 sows within 3d of breeding were allotted to one of three dietary treatments: (i) 1,500 IU/kg vitamin D₃ (CON), (ii) 500 IU/kg vitamin D₃ + 25 µg/kg 25(OH)D₃ (DL), and (iii) 1,500 IU/kg vitamin D3 + 50 µg/kg 25(OH)D₃ (DH).

As a result, concerning muscle fiber morphometrics, piglets from CON fed sows had fewer primary fibers than piglets from sows fed the DH treatment. Piglets from CON and DL fed sows showed a greater secondary to primary muscle fiber ratio compared to DH sows’ offspring. Regarding serum metabolites, treatment × time interactions were observed in both sows and their piglets. At all time periods, sow serum 25(OH)D₃ concentrations were always the greatest in sows fed the DH diet and higher at weaning for all treatments. At birth, piglets from DH fed sows had greater serum 25(OH)D₃ concentrations than piglets from sows fed the DL treatment. Finally, at weaning, serum concentrations of 25(OH)D₃ were greatest in piglets from DH sows, followed by CON fed sows’ piglets. Colostrum collected within 12 h of parturition contained less 25(OH)D₃ than milk collected on day 21 of lactation. Regardless of time, concentrations of 25(OH)D₃ in milk were higher on DH fed sows, followed by DL, and then CON.

In conclusion, combining vitamin D3 and 25(OH)D₃ in the maternal diet did not affect sow or piglet performance. However, the combination did improve the vitamin D status of the sows and their piglets and increased piglets’ primary muscle fibers at birth, though the total number of muscle fibers was not improved either at birth or at weaning.

Thayer, M. T., Nelssen, J. L., Langemeier, A. J., Morton, J. M., Gonzalez, J. M., Kruger, S. R., Ou, Z., Makowski, A. J., & Bergstrom, J. R. (2019). The effects of maternal dietary supplementation of cholecalciferol (vitamin D3) and 25 (OH) D3 on sow and progeny performance. Translational Animal Science, 3(2), 692-708. https://doi.org/10.1093/tas/txz029