Physiological stress is known to promote economic losses by causing immunosuppression. Various factors induce stress, including non-optimal management and infection with various pathogens. The concentration of the stress hormone, corticosterone, is indicative of stress in birds. However, its measurement is difficult due to its elevation caused by catching, handling, bleeding, short half-life in the blood, and short secretion period in feces. We describe a novel method to assess corticosterone concentration by sampling feathers. The viruses studied were 2 immunosuppressive viruses, Marek's disease virus and chicken anemia virus, the respiratory viruses, influenza virus H9N2, Newcastle disease virus, and Infectious bronchitis virus. The study contributes novelty as virus-induced stress by feather examination was described sporadically in chickens previously, and feathers were used to detect corticosterone mainly in dead wild and captive birds. Also, the development of extraction method from feathers is novel by using PBS instead of methanol, and by preparing the feather homogenate with steroid displacement reagent.

The study findings revealed that virus infections increased the corticosterone concentrations in feather tips to various extents, from 2× to 10× fold, demonstrating that birds endure stress in addition to the clinical and pathological effects induced by the virus infections.

众所周知，生理压力会通过引起免疫抑制来促进经济损失。各种因素都会引起压力，包括非最佳管理和感染各种病原体。应激激素皮质类固醇的浓度指示鸟类的压力。然而，由于其捕获，处理，出血，血液中半衰期短以及粪便分泌期短而引起的升高，因此很难对其进行测量。我们描述了一种通过采样羽毛评估皮质酮浓度的新颖方法。研究的病毒为2种免疫抑制病毒，马立克氏病病毒和鸡贫血病毒，呼吸道病毒，流感病毒H9N2，新城疫病毒和传染性支气管炎病毒。该研究具有新颖性，因为以前很少在鸡中通过羽毛检查对病毒引起的应激进行描述，并且羽毛主要用于死野和圈养鸟类中的皮质酮检测。而且，通过使用PBS代替甲醇，并用类固醇置换剂制备羽毛匀浆，从羽毛中提取方法的开发是新颖的。

研究发现表明，病毒感染使羽毛尖端的皮质酮浓度增加了不同程度，从2倍增加到10倍，表明除了病毒感染引起的临床和病理影响外，禽类还承受压力。