Impact of comb type on production performance, egg production quality, reproductive performance, and blood biochemical indexes in Tianfu chickens.

The comb, as a secondary sexual characteristic in chickens, serves as an important indicator of sexual maturity and potential reproductive. This study explored the relationship between comb types and production performance in Tianfu G01 chickens. Single-comb hens exhibited significantly lower laying rates compared to rose-comb hens during specific weeks (24-26, 27-28, 30, 32-34, and 38-43) but had higher average egg weights at 22, 23, 33, and 36-43 weeks. There were no significant differences in initial egg weight or 300-day body weight between the comb types. However, rose-comb hens showed higher 300-day egg production and green-shell egg rates, while single-comb hens had better egg weight and survival rates. The uterine morphology of single-comb hens was superior, with longer and wider uterine villi. Blood analysis revealed higher calcitonin and parathyroid hormone levels in single-comb hens, while rose-comb hens had higher blood calcium and phosphorus levels. In roosters, single-comb had higher germ cell counts, thicker seminiferous epithelium, and better semen quality, leading to improved fertilization rates and hatchability. These findings suggest that comb type influences both reproductive and production traits in Tianfu G01 chickens, with rose-comb favoring egg production and single-comb favoring egg weight and survival.