TY - JOUR AU - Arnold, J AU - Madson, DM AU - Ensley, SM TI - Survey of serum vitamin D status across stages of swine production and evaluation of supplemental bulk vitamin D premixes used in swine diets T2 - Journal of Swine Health and Production JF - Journal of Swine Health and Production J2 - JSHAP SN - 1537-209X DP - American Association of Swine Veterinarians PB - American Association of Swine Veterinarians DA - 2015/Jan// PY - 2015 VL - 23 M1 - 1 IS - 1 M2 - 28 SP - 28-34 L2 - https://www.aasv.org/shap/issues/v23n1/v23n1p28.html UR - https://www.aasv.org/shap/abstracts/abstract.php?v23n1p28 L1 - https://www.aasv.org/shap/issues/v23n1/v23n1p28.pdf KW - swine KW - vitamin D KW - serum KW - feed N2 - The objectives of this investigation were to evaluate the serum 25-hydroxyvitamin D [25(OH)D] concentrations in pigs of different age groups, to determine if 25(OH)D concentrations varied with season, and to assess the quality of vitamin D supplements used in swine diets from multiple commercial suppliers. Serum samples (n = 1200) submitted to a diagnostic laboratory for routine surveillance were assayed for serum 25(OH)D concentrations. Vitamin D premix samples were obtained from suppliers and analyzed at two laboratories over a 9-month period. In all age categories, 25(OH)D concentrations in numerous serum samples were lower than reference values. In the nursery, finisher, and boar age categories, there was a difference between the months of January and June (P < .05), with June samples containing higher quantities of circulating 25(OH)D. Serum samples from outdoor herds had higher 25(OH)D concentrations than samples from confined pigs (P < .01). Among the supplement samples evaluated, no individual supplement had a concentration of 25(OH)D significantly lower than 500,000 IU per g. These results revealed that commercial swine may be deficient in serum vitamin D at varying times of the year, and feed-supplement concentrations may vary. ER -