河北省舍饲绵羊的热应激评价及温湿参数与羊生理指标的相关性研究

Evaluation of Heat Stress of Housed Sheep and Correlation between Temperature-humidity Parameter and Physiological Parameter of Sheep in Hebei Province

本研究旨在评价河北省三大区域(冀北燕山、太行山区和冀中南平原)羊场夏季绵羊的热应激程度,并分析温热环境参数与绵羊个体生理指标的相关性,为改善羊舍环境提供理论依据。选择3个区域12个规模化羊场,自动检测并记录夏季羊舍的环境温度和相对湿度2个月,同时检测各场绵羊的直肠温度和呼吸频率。结果表明,冀北燕山、太行山区和冀中南平原的羊舍日均温度分别达24.3、28.5和28.7℃,温湿指数(THI)分别达72.40、79.91和79.47,冀北燕山区域绵羊正遭受轻度热应激,而太行山区和冀中南平原地区的绵羊遭受中度甚至重度热应激,可见,夏季河北省舍饲绵羊的热应激防控需要引起关注,加强夏季的防暑降温措施刻不容缓。从绵羊个体生理指标看,3个区域绵羊的直肠温度范围为39.1~39.8℃,呼吸频率为42~114次·min^-1,直肠温度与环境温度、THI之间均未表现出显著相关关系(P>0.05),但与相对湿度间表现出显著的线性负相关关系(P<0.05,r=0.60);呼吸频率与环境温度、THI之间表现出极显著正相关关系(P<0.01,r=0.84;P<0.01,r=0.87),与相对湿度间未表现出显著相关关系(P>0.05)。因此,通过羊舍温湿参数和THI的测定可以推断绵羊的个体生理状况,对实际生产中舍饲羊热应激的预防及相关疾病的诊断提供依据。

This experiment was conducted to study heat stress on sheep in three regions(Yanshan Mountain of Hebei North,Taihang Mountain and Central-South plain)of Hebei province in summer,and the correlation was also investigated between ambient temperature-humidity parameters and physiological parameters of housed sheep in order to provide theoretical basis for improving the environment of sheep shed.Twelve large-scale sheep farms in 3 regions were selected to automatically detect and record the ambient temperature and relative humidity of sheep sheds in summer for 2 months.In the mean time,the rectal temperature and respiratory rate of sheep in each farm were detected.The results showed that the average daily temperature in sheep sheds of Yanshan Mountain of Hebei North,Taihang Mountain and Central-South plain reached 24.3,28.5,and 28.7℃,and the temperature-humidity index(THI)was 72.40,79.91,and 79.47,respectively.These results suggested that sheep in Yanshan Mountain of Hebei North region were suffering from mild heat stress,while sheep in the other two regions were suffering from moderate or serious heat stress.Thus,the heat stress prevention of sheep in summer in Hebei province should be paid more attention,and it was urgent to strengthen the heat prevention and cooling measures of sheep shed in summer.From physiological parameters of sheep in 3 regions,the range of rectal temperature was from 39.1 to 39.8℃and respiratory rate was from 42 to 114 times·min^-1.There was no significant correlation between rectal temperature and ambient temperature or THI(P>0.05);however,there was a significant linear negtive correlation between rectal temperature and relative humidity(P<0.05,r=0.60).Also,an extremely significant positive correlation was observed between respiratory rate and ambient temperature(P<0.01,r=0.84)or THI(P<0.01,r=0.87);however,no significant correlation was observed between respiratory rate and relative humidity(P>0.05).In summary,the individual physiological condition of sheep can be inferred from ambient temperature,humidity parameters or THI,which can provide data for the prevention of heat stress and diagnosis of related diseases in housed sheep.