Sex-dependent regulation of pork quality traits: Multi-omics reveals nicotinamide metabolism as a key target for production optimization

Sexual dimorphism in pork quality presents economic challenges, yet the underlying molecular basis remains incompletely understood. We conducted an exploratory multi-omics study integrating transcriptomics ( n = 7 per sex), proteomics ( n = 3 per sex), and volatile compound profiling ( n = 3 per sex) in Yorkshire pigs to identify candidate sex-specific regulatory pathways. Boars showed superior growth (+10.6% ADG, P < 0.01) but inferior meat quality, including higher pH 24 h and pH 48 h , greater shear force, lower meat lightness, and lower intramuscular fat (IMF) content. Transcriptomics identified 679 differentially expressed genes (DEGs), with enrichment in metabolic and nicotinamide-related pathways (FDR < 0.05). Proteomics detected 400 differentially expressed proteins (DEPs). Volatile profiling revealed sex-specific differences in 15 flavor compounds, with aldehydes strongly associated with meat texture ( P < 0.05). Multi-omics integration revealed cross-omics consistency in nicotinamide metabolism across the transcriptomic, proteomic, and metabolite-associated analyses. These exploratory findings, derived from modest sample sizes, identify nicotinamide metabolism as a candidate molecular pathway associated with sex-specific meat quality traits. We therefore propose a working hypothesis whereby sex-dependent differences in nicotinamide metabolism may influence glycolytic flux and postmortem pH dynamics, although direct metabolite measurements and larger validation studies are still required. This study provides candidate molecular targets for future mechanistic validation and may inform subsequent breeding and nutritional studies aimed at improving meat quality in intact male pigs.