Integrative Lipidomics Reveals Schizochytrium Oil-Induced Muscle Lipid Remodeling Associated with Meat Quality, Oxidative Stability, and Flavor in Hu Lambs

Intensive grain feeding in lamb meat production can promote excessive n-6 polyunsaturated fatty acid (PUFA) deposition, which may compromise meat quality and flavor. This study investigated the response of Hu lamb meat to dietary docosahexaenoic acid (DHA)-rich Schizochytrium oil (SO), with particular attention paid to meat quality, antioxidant status, muscle lipids, and flavor. SO supplementation significantly enhanced meat lightness, activities of antioxidant enzymes, expression of antioxidant genes, DHA content, and the n-3/n-6 PUFA ratio. Lipidomic profiling detected 447 differential lipid metabolites (DLMs) between the two groups. The SO group showed higher levels of n-3 PUFAs, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), but lower levels of n-6 PUFAs, including C22:4. A flavoromic analysis identified 197 differential VOCs and showed enhanced green, fatty, and fruity aroma attributes in the SO group. Spearman correlation analysis and the random forest model were used to identify DLMs associated with differential meat quality traits, differential antioxidant enzyme activities, and key Volatile organic compounds. Three DLMs were identified as candidate lipid biomarkers, including PE(O-18:2/22:6), LPE(P-16:1), and PE(O-16:2/22:6). The results indicate that the remodeling of muscle lipids induced by SO could play a role in enhancing the quality and flavor attributes of lamb meat.