Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8.
Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A9.
Poult Sci. 2020 Dec;99(12):6753-6763. doi: 10.1016/j.psj.2020.09.051. Epub 2020 Sep 30.
Transportation of poultry is stressful, especially for end-of-cycle hens (EOCH) experiencing metabolic stress. The aim of this study was to evaluate the effects of simulated transport on well- and poor-feathered brown-strain EOCH. The study (5 × 3 × 2 factorial arrangement) consisted of 5 temperature and relative humidity (RH) combinations applied directly at crate level (-10°C uncontrolled RH [-10], +21°C 30%RH [21/30], +21°C 80%RH [21/80], +30°C 30%RH [30/30], or +30°C 80%RH [30/80]), 3 durations (4, 8, or 12 h), and 2 feather covers (well [WF] or poor [PF]). Hens (n = 540) from 3 commercial farms were housed for a 3- to 5-d adaptation period, then feed was withdrawn before treatment exposure (crate density 54.5 kg/m). Data collected included chamber conditions, feather condition score, behavior, blood physiology, core body temperature, mortality, and meat quality. Data were analyzed (randomized complete block design) using ANOVA; significance declared at P ≤ 0.05. Time spent performing thermoregulatory behaviors increased for hot (30/30 and 30/80) and cold (-10) treatments. Mortality only occurred in hens exposed to -10 and increased with longer duration. Cold exposure impacted meat quality, resulting in higher thigh pH and lower L∗ (lightness) and b∗ (yellowness). Prolonged exposure duration resulted in dehydration, indicated by blood physiology (hematocrit and hemoglobin) and live shrink. PF hens struggled with thermoregulation in -10, while WF hens struggled in 30/30 and 30/80. These results demonstrate that EOCH exposed at crate level to hot (+30) conditions experience thermal stress, while hens exposed to cold (-10) are unable to cope, compromising welfare and meat quality.
家禽运输过程中会产生应激，尤其是对于处于代谢应激状态的淘汰蛋鸡（EOC）。本研究旨在评估模拟运输对羽毛良好和较差的褐壳 EOC 的影响。该研究（5×3×2 析因设计）包括 5 种温度和相对湿度（RH）组合，直接在鸡笼水平施加，分别为：-10°C 无控 RH（-10）、+21°C 30%RH（21/30）、+21°C 80%RH（21/80）、+30°C 30%RH（30/30）或+30°C 80%RH（30/80）；3 种运输时间（4、8 或 12 小时）和 2 种羽毛覆盖物（良好[WF]或较差[PF]）。来自 3 个商业养殖场的鸡（n=540）先在笼内适应 3-5 天，然后在处理暴露前停食（鸡笼密度为 54.5kg/m³）。收集的数据包括室内环境条件、羽毛状况评分、行为、血液生理指标、核心体温、死亡率和肉质。使用方差分析（随机完整块设计）对数据进行分析；显著水平为 P≤0.05。在热（30/30 和 30/80）和冷（-10）处理下，鸡花更多时间进行体温调节行为。仅在暴露于-10°C 的鸡中出现死亡率，且随时间延长而增加。冷暴露会影响肉质，导致大腿 pH 值升高和 L∗（亮度）和 b∗（黄度）值降低。长时间暴露会导致脱水，这可通过血液生理指标（红细胞压积和血红蛋白）和活体重收缩来判断。PF 鸡在-10°C 时难以进行体温调节，而 WF 鸡在 30/30 和 30/80°C 时难以进行体温调节。这些结果表明，暴露在鸡笼水平的热（+30°C）环境中的 EOC 会经历热应激，而暴露在冷（-10°C）环境中的鸡则无法应对，这会损害福利和肉质。
