Chinese Herbal Medicine Compound Microecological Agent (C-MEA) Improves Egg Production Performance in Caged Laying Ducks via Microbiota–Gut–Ovary Axis

This study was conducted to investigate the effects of a Chinese herbal medicine compound microecological agent (C-MEA) on the egg production performance, ovarian follicle development, ovary transcriptome, and cecal microbiota of caged laying ducks. A total of 108 black Muscovy ducks (150 days old) were randomly divided into three groups for 30 days in a formal feeding trial. Compared with the control basic diet (Group C) and 16 g/kg C-MEA dosage (Group B), the 8 g/kg C-MEA dosage (Group A) increased egg production (average laying rate 69.35%) and follicle development (5~7 Fs, 6~7 LYFs, 11~13 SYFs) mass (p &lt: 0.05). According to RNA-Seq, the ovaries&rsquo: transcriptome among different dietary groups enriched six key pathways, including neuroactive ligand&ndash:receptor interaction, the PPAR signaling pathway, ECM&ndash:receptor interaction, focal adhesion, the adherens junction, and the FoxO signaling pathway, as well as 46 candidate key genes. According to 16S-Seq, the microbial diversity was significantly increased in Group A, and the genus abundances of Sphaerochaeta and UCG-004 were significantly changed among different dietary groups (p &lt: 0.05). Supplementation with C-MEA may optimize the cecal microflora and the interactions between the intestinal microflora and the host. The results from combining RNA-Seq and 16S-Seq demonstrated that the relationship between Sphaerochaeta and the hub gene cluster (F2, KNG1, C5, PLG, F2RL1, FABP1, and GCG) is the most prominent. In conclusion, the egg performance of caged laying ducks can be modulated through the microbiota&ndash:gut&ndash:ovary axis. Our findings provide new insights for improving gut health and reproductive performance of caged laying ducks.