Comparative Lipidomics and NAD⁺ Metabolism in Pectoris Muscle Reveal a Lean Metabolic Phenotype in Daweishan Miniature Chickens Versus Arbor Acre Broilers

This study aimed to compare the pectoris muscle chemical composition, NAD⁺-related metabolic regulation, and lipidomic profiles of Daweishan miniature chickens (M3) and Arbor Acre broilers (A3) to characterize breed-dependent metabolic differences. For this, 100 one-day hatched chicks were randomized into two groups (A3 and M3; n=50/breed/group) by following a completely randomized design and subjected to a 90-day feeding trial under identical conditions. At the 90 th day, six birds from each group (containing an equal number of males and females) were slaughtered, and the pectoralis muscle was sampled for subsequent analysis. The chemical composition analysis showed that the M3 group had higher crude protein and ash contents, whereas lower moisture and crude fat contents compared to the A3 group (p < 0.05). Similarly, NAD⁺ and its intermediates (nicotinamide, nicotinamide mononucleotide, and nicotinamide riboside) concentrations were also higher in the M3 group compared to the A3 group (p < 0.05). In addition, the enzymatic activities of SIRT1, LKB1, and AMPK were also greater in the M3 group than the A3 group (p < 0.05). Lipidomic profiling analysis showed distinct separation between groups, with triglyceride species downregulation, and fatty acids were upregulated in the M3 group. The KEGG pathway enrichment analysis showed that there was a significant difference in glycerolipid metabolism, fatty acid metabolism, and glycerophospholipid pathways across the groups. Correlation analysis revealed a strong association between NAD⁺ metabolites, regulatory enzymes, and differential lipid species. Based on results, the Daweishan miniature chickens maintains a metabolic phenotype characterized by enhanced NAD⁺ metabolism, greater enzymatic regulation, and reduced triglyceride accumulation, while Arbor Acre broilers exhibit a lipid deposition-oriented profile.