Multi‐omics analysis of amino acids and fatty acids metabolism impacts on flavor profiles in Tibetan and Hu sheep under cold‐season housing conditions

BACKGROUND: Different genetic backgrounds have resulted in significant differences in lamb fatty acids and amino acids, which form the basis of meat flavor. Previous studies have mainly compared grazing Tibetan sheep with lowland breeds, leaving it unclear whether breed-specific metabolic strategies persist under cold-season housing. Therefore, we integrated transcriptomics (RNA-sequencing), untargeted metabolomics (ultra high performance liquid chromatography quadrupole time of flight mass spectrometry) and volatile profiling (headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry) to explore the mechanisms of amino acids and fatty acids regulation on volatile organic compounds (VOCs) in cold-season housed Tibetan and Hu sheep. RESULTS: The results indicated that Tibetan sheep showed a relative down-regulation of thermogenesis-related genes and metabolites (e.g. PIK3R3, NADH and succinate), consistent with improved energy efficiency and associated with greater daily weight gain and intramuscular fat deposition. Key peroxisome proliferator-activated receptor-axis and lipolysis (PCK1, LIPE, ACAT1, PLIN1, AQP7 and ADIPOQ) and MMUT genes were up-regulated, corresponding to intensified lipid oxidation and Maillard reactions, and to higher relative odor activity values of aldehydes. Compared with Hu sheep, Tibetan sheep had higher concentrations of VOCs associated with fatty, citrus and sweet notes, including octanal [fold-change (FC) = 1.32, P < 0.05], decanal (FC = 1.39, P < 0.05) and 1-octen-3-ol (FC = 1.33, P < 0.05). Overall, 15 VOCs and 790 metabolites differed significantly between breeds, with Tibetan sheep showing higher levels of unsaturated fatty acids (FC = 1.69, P < 0.05). Multi-omics correlation analyses linked these metabolite and VOCs modules to intensified fatty, citrus, waxy, lemon and sweet sensory notes. CONCLUSION: This study reveals a distinct metabolic strategy in housed Tibetan sheep, where attenuated thermogenic pathways appear to divert energy toward the synthesis of flavor precursors, providing a novel molecular explanation for its unique meat quality. These breed-specific pathways highlight potential targets (e.g. LIPE and MMUT) for genetic selection or finishing strategies aimed at optimizing lamb flavor. © 2025 Society of Chemical Industry.