Effects of different feeding regimes on muscle metabolism and its association with meat quality of Tibetan sheep.

This study aimed to explore the effects of different feeding regimes on muscle metabolism and its association with meat quality of Tibetan sheep through correlation analysis of meat quality and differential metabolites using untargeted and targeted metabolomics. The untargeted metabolome was detected by UHPLC-QTOF-MS, and the targeted metabolome was detected by UHPLC-QQQ-MS (amino acids) and GC-MS (fatty acids). Based on the researched results, the nutritional quality of meat, including the content of protein and fat and the edible quality of meat, including tenderness, water holding capacity (WHC), texture, and flavor of Tibetan sheep were superior in the stall-feeding group (GBZ) than in the traditional grazing group (CBZ). In the GBZ group, the key upregulated metabolites and metabolic pathways were dominated by essential amino acids (EAAs) and amino acid metabolism as well as the key downregulated metabolites and metabolic pathways were dominated by polyunsaturated fatty acids (PUFA) and lipid metabolism. Correlation analysis showed that there was a significant correlation between the results of untargeted metabolomics and some phenotypic data, including shear force, cooking loss, drip loss, chewiness, elasticity, flavor, and the content of protein and fat. Taken together, stall-feeding would be appropriate for the production of Tibetan mutton, offering better mouthfeel and higher nutrition by altering the muscle metabolism and increasing the beneficial compound deposition in the muscle.