初生雏鸡对不同温热环境的体温调节反应

STUDY ON THE THERMOREGULATION OF NEONATAL CHICKS IN THERMAL ENVIRONMENT

用150只Hisex鉴别公雏研究了初生雏鸡的体温调节能力。试验按2×2因子设计,温度为27℃和35℃,相对湿度为35％和85％,另设对照组1。结果表明:温度、湿度对雏鸡的体温和体表温度有极显著的影响(P<0.01),温度和湿度两因子间存在有显著的交互作用(P<0.01):高温显著升高体温(P<0.01)并降低胸温(P<0.01)和背温(P<0.05);高湿度使体温显著增加(P<0.01),使体表温度降低(P<0.01)。湿度在低温下对体温无显著影响,但在高温下则加剧高温的不利影响。

One hundred and fifty one -day-old Hisex male chicks were used to investigate the development of thermoregulation of neonatal chicks. The birds were exposed to four thermal environments: 27℃ and 35% RH,27℃ and 85% RH,35℃,and 35% RH,35℃,and 85% RH. The rectal and skin temperature were determined. The results show:1.The rectal temperature was increased by high ambient temperature of high humidity. There was a significant interaction hetween temperature and humidity,the harmful effect of high ternperature on body temperature was aggravated by high humidity. 2. Under low temperature(27℃) ,the humidity had no significant effect on the rectal temperature. During the first day of exposure to 27℃,the rectal temperature of chicks had a trend to be decreased,but in the following days it was not affected by low,temperature. 3 The chest and hack temperatures were decreased by high external temperature or high humidty,and the interaction between ambient temperature and humidity was significant. It was suggested that the thermoregulation mechanism of neonatal chicks was not well developed,they were more sensitive to high external temperature than to low temperature. The reason was probable that the neonatal chicks had poor thermal resistances.