Toward sustainable livestock systems: Corn silage replacing imported hays modulates metabolism and improves meat quality in Hanwoo steers

This study evaluated the effects of partially replacing conventional hays with corn silage in total mixed rations (TMR) on growth performance, blood metabolites, meat quality traits, fatty acid profile, and lipid metabolism-related gene expression in Hanwoo steers. Sixteen Hanwoo steers were assigned at random to two dietary treatments: a conventional hay-based TMR (control) or a corn silage-replaced TMR (30 % in growing, 15 % in fattening phase) (corn silage group). Corn silage inclusion reduced blood urea nitrogen level ( p = 0.02) and urinary nitrogen excretion but had no impact on animal performance. Meat quality was improved by corn silage inclusion, as evidenced by a 12.7 % reduction in cooking loss ( p = 0.03). Meat fatty acid composition analysis showed a significantly higher proportion of unsaturated and monounsaturated fatty acids and lower saturated fatty acids in corn silage group. Furthermore, corn silage inclusion upregulated the expressions of PPARG , ACACA, FASN, SCD, CD36, ZFP423, and BSCL2 ( p < 0.05), suggesting a shift in lipid metabolic programming. Our findings suggest replacing conventional hays with corn silage may offer a sustainable and cost-effective feeding strategy, with the potential to enhance meat quality and offer practical implications for beef production systems. • Corn silage is a cost-effective alternative to conventional hays in Hanwoo steer diets. • Decreased BUN and urinary N suggest potentially reduced nitrogen emissions, supporting more environmentally friendly beef production. • Meat quality improved via reduced cooking loss and healthier fatty acid profile. • A shift in lipid metabolism is observed, characterized by a significant upregulation of key gene expressions. • Corn silage alleviated high import dependence and increased self-sufficiency, contributing to sustainable livestock farming.