Effects of vitamin A restriction on carcass characteristics, antioxidant capacity, meat quality and meat storage period of Yanbian yellow cattle.

OBJECTIVE

This study was conducted to determine effects of dietary vitamin A (VA) level and duration on intramuscular fat (IMF), meat quality, storage stability, and antioxidant gene expression in Yanbian yellow cattle.

METHODS

Twenty 15-month-old Yanbian yellow cattle (314.13±13.30 kg) were assigned to five treatments: CON (supplemental VA 2,200 IU/kg DM), NVA1 (0 IU/kg DM supplemental VA for 180 d), NVA2 (0 IU/kg DM supplemental VA for 240 d), LVA1 (supplemental VA 1,100 IU/kg DM for 180 d) and LVA2 (supplemental VA 1,100 IU/kg DM for 240 d). Growth performance, carcass traits, physicochemical characteristics, and storage stability were measured. Serum biochemical and muscle antioxidant indexes were analyzed, and the mRNA expression of antioxidant-related genes (FOXO1, GSTA1, SOD) was quantified by quantitative polymerase chain reaction. Statistical significance was set at p<0.05.

RESULTS

All VA-restricted groups showed higher IMF and marbling score, and lower muscle fiber diameter, drip loss, and shear force than the CON group (p<0.05). Serum SOD and glutathione peroxidase levels in the NVA1/NVA2 group were lower than those in the LVA groups and CON (p<0.05). During storage, NVA2/LVA1/LVA2 had lower drip loss and shear force on days 1, 3, and 5 (p<0.05); on day 7, b* was higher in NVA1/NVA2 than CON, and drip loss, cooking loss, and shear force were lower in NVA2, LVA1, and LVA2 than CON (p<0.05). At the transcriptional level, antioxidant-related genes were upregulated across all VA-restricted groups, with FOXO1 and GSTA1 peaking in LVA1 and SOD elevated in all restricted groups (p<0.05).

CONCLUSION

Restricting dietary VA to 50% of the recommended level for 180 days significantly improved marbling, tenderness, and oxidative stability without compromising growth performance. These findings highlight a feasible nutritional strategy to enhance beef quality and extend shelf life in Yanbian yellow cattle.