The effect of supplementary feed on live weight and meat quality of grazing yaks on the Qinghai-Tibetan Plateau

This study examined the effects of supplemental feeding on the weight and meat quality of grazing yaks on the Tibetan Plateau. Thirty male yaks (2.5–3 years old) with similar characteristics were randomly assigned to two groups: the traditional grazing group (G) and the supplemental feeding group (SF). The SF group received 1.5 kg of supplemental feed daily. After 120 days, slaughter performance and meat quality were compared. The results showed that the SF group had significantly higher live weight (137.2 kg vs 175.3 kg, P < 0.001) , carcass weight (63.6 kg vs 89.5 kg, P < 0.001) , and net meat yield (34.0 % vs 40.2 %, P < 0.001) compared to the G group. Moreover, the SF group exhibited lower cooking loss, drip loss, and shear force, indicating improved meat quality (P < 0.05) . Amino acid analysis revealed that the SF group had higher total amino acids (TAA, 13.25 g/100 g vs 14.14 g/100 g, P < 0.001) and essential amino acids (EAA, 5.19 g/100 g vs 6.03 g/100 g, P > 0.05) content, the ratios of EAA/TAA and EAA/NEAA increased by 4 % and 10 %, respectively. Additionally, compared to the G group, the SF group had lower saturated fatty acids (SFA, 43.25 vs 39.22, P < 0.001) and higher polyunsaturated fatty acids (PUFA 11.49 % vs 13.74 %, P < 0.001), particularly ω-3 fatty acids (2.81 % vs 5.31 %, P < 0.001), with a lower n-6/n-3 (2.88 % vs 1.44, P < 0.001) ratio. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) confirmed the effects of supplementation on amino acids and fatty acids. In conclusion, supplemental feeding significantly improved yak growth and meat quality, particularly in amino acid and fatty acid composition, providing valuable insights for grazing management on the Tibetan Plateau.