Effects of Lactiplantibacillus-plantarum-ZG7-Fermented Feed on Laying-Hen Productivity and Intestinal Health

The improvement in poultry production performance varies with different microbial strains used in fermented feed. This study investigates the efficacy of Lactiplantibacillus-plantarum-ZG7-fermented feed (ZG7-FF) on the productivity of laying hens. Results indicated that ZG7-FF significantly reduced the daily feed intake while increasing egg weight and decreasing the feed-to-egg ratio during peak production (p &lt: 0.05), in addition to enhancing the late-phase laying rate (p &lt: 0.05). Further intestinal morphological results showed that ZG7-FF significantly increased the length of villi in each intestinal segment, most significantly in the duodenum and jejunum (p &lt: 0.01). ZG7-FF also significantly increased the abundance of the phylum Desulfobacterota, while showing a notable increase in the abundance of Cyanobacteria. Conversely, there was a significant reduction in the abundance of intestinal Firmicutes (p &lt: 0.05), specifically Limosilactobacillus and Ligilactobacillus. The LEfSe (LDA Effect Size) analysis indicated that the differential species in the duodenum associated with ZG7-FF are primarily Bifidobacteriales and Aeriscardovia. In contrast, the jejunum is predominantly composed of Cyanobacteria, while the colon is mainly characterized by Enterococcus. Non-targeted metabolomics revealed that ZG7-FF drives the suppression of key metabolites, including 3-hydroxybutyric acid, ethylnitronate, 6-chlorocoumarin-3-carboxylic acid, lotaustralin, and oleoylcarnitine, while enriching pathways related to amino acid metabolism. The downregulated metabolites were functionally linked to ABC transporters and neuroactive ligand&ndash:receptor interactions. Correlation analyses demonstrated positive associations between Limosilactobacillus/Ligilactobacillus and suppressed metabolites, whereas Enterococcus and chloroplast-related taxa exhibited negative correlations. In summary, the administration of ZG7-FF significantly enhances intestinal morphology, reduces feed intake, increases egg weight, decreases ingredient usage, elevates the abundance of intestinal Enterococcus, and diminishes the overall microbial load.