Background: The testis, a critical reproductive organ in male animals, is responsible for sperm production and androgen secretion. Testis weight often correlates with reproductive performance, yet the genetic factors influencing testicular traits in chickens remain unclear. Methods: Previous genome-wide association studies (GWAS) have identified key genes affecting testicular traits in Kangle Yellow chickens, along with the associated regulatory pathways and Gene Ontology (GO) terms, through bioinformatic analyses. In this study, we utilized the existing literature, full-length transcriptome data, and proteome analyses to select key candidate genes. Results: We identified 13 associated markers for chicken testicular traits with 262 candidate genes. Nine candidate genes were found to regulate chicken testicular traits referred to integrated analysis, including CDH3, ZFPM1, CFAP52, ST6GAL1, IGF2BP2, SPG7, CDT1, NFAT5, and OPRK1. Physical interactions among these genes were also observed, implicating mechanisms such as cell adhesion molecules and neuroactive ligand–receptor interaction. Conclusions: These findings provide a genetic basis for improving testicular traits in Chinese native chicken breeds.

The impacts of omnivorous feeding on intestinal morphology and microbial community structure remain a critical area of research in poultry science, uncovering potential biological mechanisms regulating growth and development. This study investigated how feeding regimes modulate antioxidant enzyme activities, intestinal morphological structure, gut microbiota, and the relationship between gut microbiota and meat quality. We conducted a comprehensive analysis integrating antioxidant enzyme activities, intestinal histomorphology, and 16S rRNA gene sequencing. Correlation analyses were performed to identify key microbial taxa influencing meat quality. Omnivorous feeding significantly altered the activities of certain antioxidant enzymes in the serum and selected intestinal tissues of both White Recessive Rock and Xinghua chickens. Omnivorous feeding significantly reduced the VH/CD ratio in specific intestinal segments. Microbial analysis revealed that omnivorous feeding modulated the relative abundances of Bacillus, Enterococcus, Escherichia-Shigella, and Romboutsia. These shifts promoted metabolic functions, including carbohydrate, amino acid, and energy metabolism. Crucially, correlation analysis identified Faecalibacterium, Bacillus, Romboutsia, Streptococcus, and unclassified UCG_010 as key genera significantly associated with meat quality traits. The findings suggest that omnivorous feeding shows the potential to improve poultry health and meat quality.