Integrative metabolomic and transcriptomic analysis reveals stage-specific shifts in hepatic lipid metabolism of broiler chickens

Managing fat accumulation is a critical goal in the poultry industry, with the liver being the primary site for lipid metabolism in chickens. This study used non-targeted metabolomics to investigate dynamic changes in metabolite composition in chicken liver across five physiological stages. A total of 1121 metabolites were identified, with 749 and 372 detected in positive- and negative-ion modes, respectively. The regulation of hepatic lipolysis involves numerous metabolic pathways, making it a complex process. We performed trend analysis of lipid, carbohydrate and amino acid-related metabolites. Age exerted major effects on hepatic metabolism, significantly enriching pathways including alpha-linolenic acid metabolism, linoleic acid metabolism, steroid hormone biosynthesis, 2-oxocarboxylic acid metabolism and nicotinate and nicotinamide metabolism. Transcriptomic analysis identified 12 lipid-metabolism-related genes, showing a tendency of continuously increase. Potential functional genes influencing lipid metabolism-related pathways were identified through a comprehensive analysis of differential lipid-related metabolites and genes, including <i>fatty acid desaturase 2</i> (<i>FADS2</i>), <i>acetyl-CoA acetyltransferase 2</i> (<i>ACAT2</i>), <i>apovitellenin 1</i> (<i>APOV1</i>), <i>vitellogenin 1</i> (<i>VTG1</i>), <i>membrane-bound O-acyltransferase domain-containing protein 2</i> (<i>MBOAT2</i>) <i>and ELOVL fatty acid elongase 1</i> (<i>ELOVL1</i>). These findings could help improve understanding of hepatic metabolism during different physiological stages and identify valuable biomarkers for specific metabolite accumulation.