Effects of Ante-Mortem Vitamin D3 Supplementation on Meat Quality in Yanbian Yellow Bulls

This preliminary study investigated the effects of ante-mortem Vitamin D3 (VD3) supplementation on blood parameters and meat quality in Yanbian yellow bulls. Twenty healthy Yanbian yellow bulls (intact male Yanbian yellow bulls, 30 ± 1 months of age; initial body weight 534 ± 15 kg) were allocated into five groups: a control (basal diet) and four treatment groups with varying VD3 regimens (3 × 106 or 6 × 106 IU/d for 7 days, with or without a 7-day withdrawal). Results demonstrated that, compared to the control group, VD3 supplementation elevated serum calcium (p < 0.01) and phosphorus levels (p < 0.05) while enhancing antioxidant capacity (p < 0.05) and immunoglobulin production (p < 0.01). Muscle calcium deposition increased (p < 0.01), accompanied by higher meat lightness (CIE L*) values (p < 0.01) and reduced drip loss rate (p < 0.01). Shear force decreased across cuts (p < 0.01), which was linked to calpain-mediated protein degradation and sarcomere elongation (p < 0.01). Under the conditions of this study, the protocol involving 3.0 × 106 IU/d VD3 supplementation for 7 days followed by a 7-day withdrawal yielded the most favorable outcomes. These findings suggest a potential strategy to improve beef quality by regulating calcium homeostasis and enhancing muscle proteolysis, warranting further validation in larger populations.