Li Dapeng, Li Fuwei, Liu Wei, Han Haixia, Wang Jie, Hao Dan, Sun Yan
Poultry Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Shandong Provincial Key Laboratory of Livestock and Poultry Breeding, Jinan 250100, China.
Animals (Basel). 2025 Jun 16;15(12):1769. doi: 10.3390/ani15121769.
Controlling low ambient temperatures and ammonia levels is critical for effective environmental management in poultry houses during winter, as both represent persistent stressors affecting bird health and productivity. However, evidence regarding their combined long-term effects on the physiological responses of laying hens remains limited. In this study, 576 eighteen-week-old Hy-Line Brown hens were randomly assigned to six treatments (8 replicates with 12 birds per replicate each treatment) and housed in environmentally controlled chambers for 20 weeks: T1 (8 °C, ≤5 ppm ammonia), T2 (8 °C, 20 ppm ammonia), T3 (8 °C, 45 ppm ammonia), T4 (20 °C, ≤5 ppm ammonia; control), T5 (20 °C, 20 ppm ammonia), and T6 (20 °C, 45 ppm ammonia). Plasma samples were collected at 22, 26, 30, 34, and 38 weeks to evaluate physiological stress biomarkers (corticosterone, CORT; total antioxidant capacity, T-AOC), immunoglobulins (IgG, IgM, and IgA), and reproductive hormones (luteinizing hormone, LH; follicle-stimulating hormone, FSH; estradiol, E2). At 38 weeks, hypothalamus, pituitary, and spleen tissues were collected to assess the relative mRNA expression of gonadotropin-releasing hormone (GnRH), FSH, tumor necrosis factor-α (TNF-α), and interleukins (IL-1β, IL-6, and IL-10). Results showed that both cold and ammonia stress reduced antioxidant capacity, disrupted immune homeostasis, and altered reproductive hormone profiles. Cold exposure induced acute immunoendocrine alterations with partial physiological adaptation over time, whereas ammonia exerted progressive and cumulative damage, including elevated immunoglobulins (IgG and IgM) and downregulation of GnRH and FSH expression. Combined exposure significantly upregulated TNF-α and IL-1β expression, suggesting a synergistic inflammatory response. These results highlight complex, parameter-specific interactions between cold and ammonia stressors, emphasizing the need for targeted environmental strategies. Stage-specific interventions-thermal regulation in early laying and ammonia control in later phases-are recommended to safeguard hen health and optimize productivity under winter conditions.
在冬季，控制较低的环境温度和氨气水平对于家禽舍的有效环境管理至关重要，因为这两者都是影响禽类健康和生产力的持续性应激源。然而，关于它们对蛋鸡生理反应的长期综合影响的证据仍然有限。在本研究中，576只18周龄的海兰褐蛋鸡被随机分配到6种处理组（每个处理组8个重复，每个重复12只鸡），并在环境控制舱中饲养20周：T1（8℃，氨气浓度≤5 ppm），T2（8℃，氨气浓度20 ppm），T3（8℃，氨气浓度45 ppm），T4（20℃，氨气浓度≤5 ppm；对照组），T5（20℃，氨气浓度20 ppm），以及T6（20℃，氨气浓度45 ppm）。在22、26、30、34和38周时采集血浆样本，以评估生理应激生物标志物（皮质酮，CORT；总抗氧化能力，T-AOC）、免疫球蛋白（IgG、IgM和IgA）以及生殖激素（促黄体生成素，LH；促卵泡生成素，FSH；雌二醇，E2）。在38周时，采集下丘脑、垂体和脾脏组织，以评估促性腺激素释放激素（GnRH）、FSH、肿瘤坏死因子-α（TNF-α）以及白细胞介素（IL-1β、IL-6和IL-10）的相对mRNA表达。结果表明，寒冷和氨气应激均降低了抗氧化能力，破坏了免疫稳态，并改变了生殖激素谱。寒冷暴露会引发急性免疫内分泌改变，并随着时间推移出现部分生理适应，而氨气则会造成渐进性和累积性损伤，包括免疫球蛋白（IgG和IgM）升高以及GnRH和FSH表达下调。联合暴露显著上调了TNF-α和IL-1β的表达，表明存在协同炎症反应。这些结果突出了寒冷和氨气应激源之间复杂的、参数特异性的相互作用，强调了针对性环境策略的必要性。建议采取分阶段干预措施——产蛋初期进行温度调节，后期控制氨气——以保障母鸡健康并在冬季条件下优化生产力。
