Muiruri H K, Harrison P C
Department of Animal Sciences, University of Illinois, Urbana 61801.
Poult Sci. 1991 Nov;70(11):2253-8. doi: 10.3382/ps.0702253.
A split-plot experiment was conducted in thermally controlled chambers using Columbian Plymouth Rock chickens to determine the effect of water-cooled roosts on performance in hot ambient conditions. The birds were subjected to 25 +/- 1, 35 +/- 1, and 25 +/- 1 C ambient temperature treatments for 2, 3, and 2 wk, respectively. Roost temperature treatments were either cool (20 +/- 1 C) or air-equilibrated (25 +/- 1 or 35 +/- 1 C). The performance parameters evaluated were percentage hen-day egg production, egg weight, feed intake, feed conversion, fertility, and hatchability. Birds subjected to the water-cooled roost treatment had consistently higher performance than birds using the air-equilibrated roost under all three ambient temperatures. Both ambient and roost temperature treatments significantly influenced percentage hen-day egg production, average daily feed intake, and percentage hatchability (P less than or equal to .05). However, the biggest differences in performance were observed during the heat-stress period. Decreases in performance during the heat-stress period from the thermoneutral control values were: 5.95 and 13.1 percentage points for hen-day egg production, 22.2 and 34.8 percentage points for average daily feed intake, and 5.17 and 15.38 percentage points for hatchability in water-cooled and air-equilibrated roost treatments, respectively. The ambient and roost temperature treatments did not significantly affect egg weight, feed conversion, or percentage fertility. The improved performance with water-cooled over air-equilibrated roost treatments, especially during heat-stress periods, indicates that the water-cooled roosts minimized the deleterious effects of heat stress through conductive heat loss from the birds to the roost.
在温度可控的试验箱中，以哥伦比亚普利茅斯洛克鸡进行了一项裂区试验，以确定水冷栖架对炎热环境条件下生产性能的影响。试验鸡分别在25±1℃、35±1℃和25±1℃的环境温度处理下饲养2周、3周和2周。栖架温度处理分为凉爽（20±1℃）或与空气平衡（25±1℃或35±1℃）。评估的生产性能参数包括母鸡日产蛋率、蛋重、采食量、饲料转化率、受精率和孵化率。在所有三种环境温度下，接受水冷栖架处理的鸡的生产性能始终高于使用空气平衡栖架的鸡。环境温度和栖架温度处理均显著影响母鸡日产蛋率、平均日采食量和孵化率（P≤0.05）。然而，在热应激期观察到生产性能的最大差异。与热中性对照值相比，热应激期水冷栖架处理和空气平衡栖架处理的母鸡日产蛋率分别下降5.95和13.1个百分点，平均日采食量分别下降22.2和34.8个百分点，孵化率分别下降5.17和15.38个百分点。环境温度和栖架温度处理对蛋重、饲料转化率或受精率没有显著影响。与空气平衡栖架处理相比，水冷栖架处理能提高生产性能，尤其是在热应激期，这表明水冷栖架通过鸡向栖架的传导散热，将热应激的有害影响降至最低。
