Age-Driven Proteomic Networks in Ningxiang Pig Backfat Identify Candidate Regulators of Carcass Traits

Indigenous pigs constitute crucial genetic reservoirs. Adipose tissue is central to pig growth and metabolism, yet its molecular ontogeny remains poorly characterized in indigenous breeds such as the Ningxiang pig. We employed mass spectrometry to profile backfat proteomes across six postnatal stages (60-360 days). Proteomes clearly separated early (60-120 days) from late stages (300-360 days). Older pigs showed enrichment in processes linked to energy metabolism, translation, immune function, and mitochondrial activity. We identified 43 lipid metabolism proteins exhibiting significant age-dependent abundance. Weighted co-abundance network analysis revealed four protein modules significantly correlated with lean meat percentage, fat percentage, and carcass weight. Intramodular analysis identified four hub proteins-ALDH18A1, FABP4, FBP1, and HADHB-as putative candidates associated with lipid transport, gluconeogenesis, and fatty acid oxidation. This study links temporal proteomic profiles with key carcass traits, providing a data resource and a network-based framework for future research.