Vitamin A-activated PPARγ signaling enhances intramuscular fat accumulation by overriding AMPK-mediated inhibition in late-fattening beef cattle

Strategic late-fattening VA supplementation enhances marbling development through PPARγ-mediated transcriptional networks, with AMPK serving as a metabolic sensor and negative feedback regulator rather than an absolute inhibitor. This stage-specific intervention achieved superior marbling quality and improved fatty acid composition in Woking black cattle, suggesting potential for optimization of premium beef production. Validation across diverse genetic backgrounds and production systems will be essential for broader industry implementation.