Exploration of microorganism and metabolites relation to the egg production of Shanma ducks based on 16S rRNA gene sequencing and metabolomics

Gut microbiota and metabolites play crucial roles in regulating poultry health, metabolism, and egg-laying performance. To elucidate the biological basis underlying differences in laying performance, this study employed 16S rRNA high-throughput sequencing and untargeted liquid chromatography-mass spectrometry (LC-MS/MS) to analyze the gut microbiota and serum metabolome of low-producing (LP) and high-producing (HP) Shanma ducks. The LP and HP groups exhibited significant differences in egg production performance, body size parameters, and slaughter traits. Firmicutes were the dominant phylum in the gut microbiota of both groups. However, Actinobacteria were significantly enriched in the HP group, while Campylobacter was more abundant in the LP group. Correlation analysis revealed a negative association between Campylobacter abundance and egg production, whereas Corynebacterium (belonging to Actinobacteria) showed a positive correlation. Non-targeted serum metabolomic analysis indicated that the differentially expressed metabolites were primarily enriched in nucleotide metabolism, choline metabolism, and glycerophospholipid metabolism pathways. Notably, Campylobacter abundance was negatively correlated with the levels of key metabolites involved in these pathways. Mantel analysis further confirmed a strong correlation between egg production and both gut microbiota composition and serum metabolomic profiles. Collectively, these findings provide new insights into the microbial and metabolic determinants of reproductive performance in ducks, offering a foundation for genetic selection and microbiota-targeted nutritional strategies to enhance laying efficiency in Shanma ducks.