Li F K, Yang Y, Jenna K, Xia C H, Lv S J, Wei W H
College of Bio-science & Bio-technology, Yangzhou University, Yangzhou, China.
College of Agriculture and Forestry, Linyi University, Linyi, China.
Trop Anim Health Prod. 2018 Dec;50(8):1893-1901. doi: 10.1007/s11250-018-1642-3. Epub 2018 Jul 14.
This study was conducted to investigate the effects of heat stress on the behavioral and physiological patterns in Small-tail Han sheep housed indoors in summer without climate control. Sixteen adult animals were allocated into two groups of eight animals, based on sex: one group of eight rams and one group of eight ewes. Temperature-humidity index (THI) was used to assess the degree of heat stress. All sheep were subjected to a 10-day pre-experimental period of habituation to the experimental feed and environment. Physiological parameters monitored were respiratory rate (RR), rectal temperature (RT), and heart rate (HR). Blood chemistry parameters were also recorded, including plasma minerals and blood metabolites, from jugular vein blood samples. Behavioral parameters were lying, standing, excreting, drinking, foraging, walking, and ruminating. The research findings showed that there were some significant differences of behavior (standing, P = 0.001; walking, P = 0.049; ruminating, P = 0.010), physiology (RR, P = 0.0001; HR, P = 0.002; RT, P = 0.03;) and plasma minerals and blood metabolites (sodium, P = 0.047; phosphorus, P = 0.002; T4, P = 0.041; cortisol, P = 0.0047; triglyceride, P = 0.009) between ram and ewe and that heat stress also significantly affected (P < 0.05) standing, lying, foraging and drinking behavior, all of the physiological parameters and some of the blood chemistry parameters (chlorides, sodium, phosphorus, total protein, tetraiodothyronine, cholesterol, triglyceride, creatinine, cortisol, and glucose). These results indicate that ewe has better high-temperature tolerance than ram, and heat stress can alter behavioral and physiological patterns in Small-tail Han sheep housed indoors. These changes may allow the sheep to adapt better to the ambient temperature.
本研究旨在调查夏季在无气候控制的室内饲养的小尾寒羊热应激对其行为和生理模式的影响。16只成年羊按性别分为两组，每组8只：一组为8只公羊，另一组为8只母羊。采用温湿度指数（THI）评估热应激程度。所有绵羊都经过为期10天的预实验期，使其适应实验饲料和环境。监测的生理参数包括呼吸频率（RR）、直肠温度（RT）和心率（HR）。还从颈静脉血样中记录了血液化学参数，包括血浆矿物质和血液代谢物。行为参数包括躺卧、站立、排泄、饮水、觅食、行走和反刍。研究结果表明，公羊和母羊在行为（站立，P = 0.001；行走，P = 0.049；反刍，P = 0.010）、生理（RR，P = 0.0001；HR，P = 0.002；RT，P = 0.03）以及血浆矿物质和血液代谢物（钠，P = 0.047；磷，P = 0.002；T4，P = 0.041；皮质醇，P = 0.0047；甘油三酯，P = 0.009）方面存在一些显著差异，并且热应激也显著影响（P < 0.05）站立、躺卧、觅食和饮水行为、所有生理参数以及一些血液化学参数（氯化物、钠、磷、总蛋白、甲状腺素、胆固醇、甘油三酯、肌酐、皮质醇和葡萄糖）。这些结果表明，母羊比公羊具有更好的高温耐受性，热应激可改变室内饲养的小尾寒羊的行为和生理模式。这些变化可能使绵羊更好地适应环境温度。
