Darre M J, Harrison P C
Poult Sci. 1987 Mar;66(3):541-7. doi: 10.3382/ps.0660541.
Two experiments were undertaken to determine selected cardiovascular responses of laying hens to a thermal challenge at 35 C ambient temperature. In the first, six Single Comb White Leghorn (SCWL) hens were exposed to 35 C and changes in systolic and diastolic blood pressure, heart rate, respiratory rate, and rectal temperatures were determined. In the second, seven SCWL hens were exposed to 35 C and changes in cardiac output, total peripheral resistance, blood pressure, heart rate, respiratory rate, and rectal temperature were monitored. In the first experiment heart rate and blood pressure decreased. In the second experiment there was a 58% increase in cardiac output and a 50% decrease in total peripheral resistance accompanied by a 9% decrease in mean blood pressure. Changes in cardiovascular tone preceded respiratory adjustments during acute heat challenges. This may represent one of the most efficient means of heat dissipation for the bird.
进行了两项实验，以确定产蛋母鸡在35摄氏度环境温度下受到热应激时的特定心血管反应。在第一项实验中，六只单冠白来航（SCWL）母鸡暴露于35摄氏度环境，测定收缩压和舒张压、心率、呼吸频率和直肠温度的变化。在第二项实验中，七只SCWL母鸡暴露于35摄氏度环境，监测心输出量、总外周阻力、血压、心率、呼吸频率和直肠温度的变化。在第一项实验中，心率和血压下降。在第二项实验中，心输出量增加了58%，总外周阻力降低了50%，同时平均血压下降了9%。在急性热应激期间，心血管张力的变化先于呼吸调整。这可能是禽类最有效的散热方式之一。
