Qi Kunlong, Amevor Felix Kwame, Liu Zheliang, He Juan, Xu Dan, Zhai Chencan, Wang Yingjie, Wu Liuting, Wang Yan, Shu Gang, Zhao Xiaoling
State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, PR China; Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, Sichuan Agricultural University, Chengdu, Sichuan, PR China.
Department of Basic Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, PR China.
Poult Sci. 2025 Aug;104(8):105367. doi: 10.1016/j.psj.2025.105367. Epub 2025 May 28.
The comb, a secondary sexual characteristic in chickens, plays a crucial role in sexual selection, physiological regulation, and growth performance. This study explores the relationship between comb development, circulating hormone levels, and growth traits in Tianfu broilers. Weekly measurements of comb size and body weight from hatching to market age (day 70) revealed significant individual variations in comb traits. Based on comb size, chickens were categorized into large comb and small comb groups at market age. Histological analysis revealed that chickens with large combs exhibited thicker dermal, but the central layer exhibits the opposite, with sex-specific differences in collagen fiber content and epithelium thickness. Additionally, while only a few lymphocytes were observed in the combs of the large-comb group, focal lymphocyte aggregation was evident in the small-comb group. Circulating growth hormone (GH) and testosterone levels were significantly higher in chickens with large combs, particularly in roosters, where testosterone levels showed a significant correlation with testicular weight. It was observed that the GH levels were significantly correlated with comb development, independent of sex. Correlation analysis indicated a trade-off between comb size and carcass yield, suggesting that resource allocation favors ornamentation and reproductive system over meat production. These findings provide insights into the biological significance of comb development, emphasizing its potential as a marker for reproductive fitness and immunomodulatory functions in poultry breeding.
鸡冠是鸡的第二性征，在性选择、生理调节和生长性能方面发挥着关键作用。本研究探讨了天府肉鸡鸡冠发育、循环激素水平和生长性状之间的关系。从孵化到上市日龄（第70天）每周测量鸡冠大小和体重，结果显示鸡冠性状存在显著的个体差异。根据鸡冠大小，在上市日龄时将鸡分为大鸡冠组和小鸡冠组。组织学分析表明，大鸡冠鸡的真皮较厚，但中间层情况相反，在胶原纤维含量和上皮厚度方面存在性别特异性差异。此外，在大鸡冠组的鸡冠中仅观察到少量淋巴细胞，而小鸡冠组则有明显的局灶性淋巴细胞聚集。大鸡冠鸡的循环生长激素（GH）和睾酮水平显著更高，尤其是在公鸡中，睾酮水平与睾丸重量呈显著相关。研究发现，GH水平与鸡冠发育显著相关，且不受性别影响。相关性分析表明，鸡冠大小与胴体产量之间存在权衡，这表明资源分配有利于装饰和生殖系统而非肉类生产。这些发现为鸡冠发育的生物学意义提供了见解，强调了其作为家禽繁殖中生殖适应性和免疫调节功能标志物的潜力。
