Evaluation of the effect of exogenous 25-(OH)D3 vitamin administration on colostral and serum cytokine levels, lactoferrin and IgG concentration in prepartum period holstein heifer.

The aim of this study was to evaluate the effects of a single dose of 25-(OH)D3 vitamin injection in pregnant holstein heifers on cytokine concentrations (IL-6 and IFN-γ) in heifer colostrum and serum, colostral lactoferrin, and IgG and vitamin D concentrations in calves. The control group (n: 10) and the vitamin D group (n: 10) were composed of heifer Holstein 8 ± 2 days before calving. Blood samples were collected on day 265 ± 2 of gestation in the vitamin D and control groups, before vitamin D and physiological saline administration, and at the time of parturition. Colostrum and serum samples were analyzed for lactoferrin, IgG, IL-6, and IFN-γ by bovine-specific ELISA, solid-matter digital refractometry, and vitamin D by LC-MS/MS. The colostral IFN-γ (p < 0.015), IgG (p < 0.035), lactoferrin (p < 0.001), and Brix (p < 0.035) concentrations of the vitamin D group were significantly higher than those of the control group. Serum IL-6 (p<0.002) and IF-γ (p<0.001) concentrations were significantly lower in the group that received vitamin D at parturition compared to the control group. In contrast, serum 25-(OH)D concentrations in heifers treated with vitamin D were significantly higher than in the control group (p<0.003). The serum 25-(OH)D concentration of calves born from heifers administered vitamin D was significantly higher than the control group (p < 0.006). Serum vitamin D concentration in calving cows showed a negative correlation with IL-6 (r=-0.663, p<0.001) and IFN-γ (r=-0.687, p<0.001) levels, while it showed a positive correlation with colostrum IFN-γ (r=0.446, p<0.048), colostral lactoferrin (r=0.686, p<0.001), and calf serum vitamin D concentration (r=0.598, p<0.005). In conclusion, this study determined that administering vitamin D to holstein heifer increased colostrum cytokine concentrations and lactoferrin levels, decreased serum pro-inflammatory cytokine concentrations at parturition, and increased colostrum IgG and Brix values. Additionally, the increased serum vitamin D concentration had a positive impact on the health and well-being of the animals by suppressing inflammatory cytokines. Vitamin D supplementation in holstein heifers can increase vitamin D levels in calves and significantly improve colostrum quality and cow health.