Comparative Metabolomics and Lipidomics of Meat from Duroc × Guangdong Small-Eared Spotted Pigs and Commercial Duroc × (Landrace × Yorkshire) Pigs

Crossbreeding with indigenous breeds is an important approach for improving pork quality. In this study, untargeted metabolomics and targeted lipidomics were applied to comprehensively characterize meat quality, metabolites, and lipids in Duroc × Guangdong small-ear spotted (DG) and commercial Duroc × (Landrace × Yorkshire) (DLY) pigs. Multivariate statistical analysis was used for differential comparison, compound screening, and breed discrimination. DG pigs presented better tenderness than DLY pigs, although their meat color and marbling scores were lower. Protein, amino acid, and fatty acid contents did not differ significantly between breeds (p > 0.05), but their metabolomic and lipidomic profiles showed marked differences. Metabolomics identified 13 differential metabolites, such as L-norleucine and L-phenylalanine. Lipidomics revealed 77 lipids with differential abundance between the two breeds, predominantly triglycerides and ceramides, with 76 being more abundant in DG pigs. KEGG enrichment analysis showed that amino acid metabolism was the main pathway enriched by the differential metabolites, whereas the differential lipids were primarily involved in glycerolipid metabolism and other related pathways. Correlation analysis indicated that breed influenced relationships among meat quality traits, metabolites, and lipids. These findings offer molecular insights into the meat quality characteristics of indigenous crossbred pigs.