Abstract
Crossbreeding serves as a foundational approach in establishing novel livestock and poultry varieties, enhancing both production efficiency and economic viability. The Ningdu Hybrid Yellow chicken represents a recently cultivated hybrid line exhibiting superior growth characteristics. Nevertheless, comprehensive investigations comparing intestinal microbiota profiles and serum metabolic signatures between this hybrid strain and its parental lines (H and G) remain scarce. Our study employed 16S rRNA gene sequencing coupled with LC-MS/MS metabolomics to systematically analyze microbial community structures and serum metabolite variations across these three groups. The hybrid (W) group demonstrated enriched abundance of beneficial gut microbiota including Aeriscardovia, Bacillus, Romboutsia, Faecalibacterium, and Companilactobacillus. KEGG pathway analysis revealed that differentially expressed metabolites (DEMs) in the W vs. H comparison were primarily enriched in amino acid and protein metabolic pathways, whereas the W vs. G comparison demonstrated predominant associations with lipid and lipid-like molecule metabolism. Network correlation analyses identified robust associations between signature microbial taxa and DEMs across all groups. These findings establish a theoretical framework for optimizing breeding strategies and commercial applications of Ningdu Yellow chickens.