Department of Animal Science and Technology, Chung-Ang University, Gyeonggi-do, Republic of Korea.
Department of Animal Science and Technology, Chung-Ang University, Gyeonggi-do, Republic of Korea.
Poult Sci. 2022 Jun;101(6):101868. doi: 10.1016/j.psj.2022.101868. Epub 2022 Mar 25.
The objective of the current experiment was to compare various stress biomarkers including the heterophil to lymphocyte ratio (H:L ratio) in blood and the corticosterone (CORT) concentrations in feathers, claws, and egg yolk and to find the potential stress biomarkers in laying hens exposed to a long-term multiple stress condition. A total of 24 Hy-Line Brown laying hens at 47 wk of age were allotted to 2 distinct conditions including normal condition (NC) and multiple stress condition (MC) with 8 replicated cages. In NC treatment, 8 hens were raised individually in the cage (0.16 m/hen) under the temperature of 21 ± 0.6°C. In MC treatment, 16 hens were raised with 2 hens per cage to decrease space allowance (0.08 m/hen) and the temperature was maintained at 31 ± 1.6°C. The experiment lasted for 8 wk. The common diets and water were fed on an ad libitum basis during the experiment. Results indicated no interactions between stress conditions and duration of stress exposure for all measurements. Hens in MC treatment had a greater (P < 0.01) blood H:L ratio than those in NC treatment. The greater (P < 0.05) H:L ratio for MC treatment was observed at all weeks. Hens in MC treatment had greater (P < 0.05) feather CORT concentrations than those in NC treatment. Feather CORT concentrations were increased (P < 0.05) with duration of the experiment. However, stress conditions did not influence claw CORT concentrations. A tendency (P = 0.081) was observed for greater yolk CORT concentrations in MC treatment than in NC treatment. In conclusion, the H:L ratio in blood and CORT concentrations in feathers and egg yolks are considered potential stress biomarkers in laying hens exposed to stress conditions, although each measurement has its respective limitations. However, CORT concentrations in the claw appear to be insensitive to a long-term stress exposure.
本实验旨在比较血液中的异嗜性白细胞与淋巴细胞比值（H:L 比值）和羽毛、爪和蛋黄中的皮质酮（CORT）浓度等各种应激生物标志物，以寻找暴露于长期多重应激条件下的产蛋母鸡的潜在应激生物标志物。将 24 只 47 周龄的海兰褐产蛋母鸡分为正常条件（NC）和多重应激条件（MC）2 种不同条件，每组 8 个重复笼。在 NC 处理中，8 只母鸡在笼中单独饲养（每只鸡 0.16m2），温度为 21±0.6°C。在 MC 处理中，16 只母鸡每笼饲养 2 只，以减少空间（每只鸡 0.08m2），温度保持在 31±1.6°C。实验持续 8 周。实验期间，母鸡自由采食普通饲料和饮水。结果表明，所有测量指标均无应激条件和应激暴露时间的相互作用。MC 处理组母鸡的血液 H:L 比值大于 NC 处理组（P<0.01）。MC 处理组的 H:L 比值在所有周都较大（P<0.05）。MC 处理组母鸡的羽毛 CORT 浓度大于 NC 处理组（P<0.05）。随着实验时间的延长，羽毛 CORT 浓度增加（P<0.05）。然而，应激条件并不影响爪 CORT 浓度。MC 处理组蛋黄 CORT 浓度有高于 NC 处理组的趋势（P=0.081）。总之，血液中的 H:L 比值和羽毛及蛋黄中的 CORT 浓度被认为是暴露于应激条件下的产蛋母鸡的潜在应激生物标志物，尽管每种测量方法都有其各自的局限性。然而，爪中的 CORT 浓度似乎对长期应激暴露不敏感。
