Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A9.
Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8.
Poult Sci. 2017 Sep 1;96(11):3836-3843. doi: 10.3382/ps/pex220.
The influence of hot conditions on 12-week-old turkey hens and 16-week-old toms while crated at transport density was evaluated. Forty-eight hens and 48 toms (8 birds per flock × 3 flocks × 2 humidity levels) were used in neutral treatments (trt; 20°C), and 16 hens and 16 toms (8 birds per flock × 1 flock × 2 humidity levels) were used in the hot trt (35°C). Birds were placed in crates at a transport stocking density of approximately 83 kg/m2, then inside a pre-conditioned chamber for 8 hours. Live shrink, core body temperature (CBT), heterophil/lymphocyte (H/L) ratio, and breast and thigh pH and color were recorded. Differences were declared significant at P ≤ 0.05. Live shrink after exposure to the 35°C trt (4.92%) was greater (P < 0.0001) than when birds were exposed to 20°C (1.48%). The 35°C trt (P < 0.0001) had higher Δ CBT (final minus initial) compared to the 20°C trt. The 35°C trt also caused higher (P < 0.0001) H/L ratio, 4.07 vs. 1.57 for the 20°C trt. Breast (P = 0.0110) and thigh pH levels (P < 0.0001) measured 27 h postmortem were lower for the 35°C trt at 5.64 and 5.73 compared to the 20°C trt at 5.70 and 5.92, respectively. Breast meat from birds exposed to 35°C was darker (P < 0.0001), while the color of thigh meat was unaffected. Toms quickly became distressed in the hot conditions, forcing those tests to be aborted. Only CBT data were analyzed. The CBT increased at a mean rate of 0.09°C/min for hens at both RH levels, while the CBT of toms increased at 0.12 and 0.18°C/min when exposed to 35°C, 30%; and 35°C, 80%, respectively. Exposure to hot temperatures caused higher CBT, greater live shrink, and greater H/L ratio. Toms were more greatly affected than hens to the hot trt, with CBT increasing at a greater rate.
评估了在运输密度下，热条件对 12 周龄火鸡母鸡和 16 周龄公鸡的影响。中性处理（trt；20°C）中使用了 48 只母鸡和 48 只公鸡（每群 8 只×3 群×2 个湿度水平），而在热 trt（35°C）中使用了 16 只母鸡和 16 只公鸡（每群 8 只×1 群×2 个湿度水平）。鸡被放置在运输笼中，密度约为 83 kg/m2，然后在预调节室中放置 8 小时。记录活重损失、核心体温（CBT）、异嗜/淋巴细胞（H/L）比值以及胸肌和大腿 pH 值和颜色。差异在 P ≤ 0.05 时被宣布为显著。暴露于 35°C trt 后的活重损失（4.92%）高于暴露于 20°C trt 时的活重损失（1.48%）（P < 0.0001）。与 20°C trt 相比，35°C trt 的 Δ CBT（最终减去初始值）更高（P < 0.0001）。35°C trt 还导致更高的 H/L 比值（4.07 比 1.57）（P < 0.0001）。27 小时后，胸部（P = 0.0110）和大腿 pH 值（P < 0.0001）的测量值在 35°C trt 下分别为 5.64 和 5.73，而在 20°C trt 下分别为 5.70 和 5.92。暴露于 35°C 的鸡的胸肉颜色更暗（P < 0.0001），而大腿肉的颜色不受影响。公鸡在热条件下很快变得痛苦，迫使这些测试中止。仅分析了 CBT 数据。在两种 RH 水平下，母鸡的 CBT 平均以 0.09°C/min 的速度升高，而公鸡的 CBT 分别以 0.12°C/min 和 0.18°C/min 的速度升高，当暴露于 35°C，30%和 35°C，80%时。暴露于高温会导致更高的 CBT、更大的活重损失和更高的 H/L 比值。与母鸡相比，公鸡受到热 trt 的影响更大，CBT 增加的速度更快。
