家畜环境卫生学：第二章 温热环境.ppt

Respiratoryrates(RR,mean,pooledSE=9.1breaths/min)andairtemperaturesforindoorandoutdoorgestatingandlactatingsows(n=6/condition).Indoorsowshaddripcoolingwhileoutdoorsowshadmudwallows.IndoorOutdoorItemTempoCRRbreaths/minTempoCRRbreaths/min妊娠3367.83332.7哺乳2852.23337.5Average60.035.1mudwallows屋顶隔热WallowTips足够面积（二倍）泥浆不应过浓厚-可流动设有供饮用清水在过高温时，应可遮荫第四节体温的日节律结果产热恒温动物用以维持内核温度调节方式.依靠化学性代谢调节产生热能Thermogenesis:颤抖Shivering利用肌肉收缩产生热能收缩性骨骼肌群之肌紧张短时间的颤抖肌肉活化释放ATP水解供给收缩之能量拮抗肌互动Thermogenesis:非颤抖Nonshivering脂肪代谢酶系统活化交感神经系统（sympatheticnervoussystem，SNS)活化.脂肪氧化供能仅有少数能量以ATP方式蓄积两种调节机制SNS活化脂肪细胞正常ATP代谢途径ATP水解提供做功和热量褐色脂肪组织（BrownFat）AdaptationsforColdEnvironments竖毛（Fluffing）下临界温度皮肤的竖毛肌（pilomotormuscles）使被毛或羽毛竖立提供厚空气层AdaptationsforColdEnvironmentsQ:Whichanimalwouldbeabletostaywarmerandwhy?AdaptationsforColdEnvironments北极熊（POLARBEAR）大动物有较低传热比b/c通常具有较大隔热性（insulation）单位体积的表面积相对小散热少AdaptationsforColdEnvironments隔热（Insulation）:鲸脂Blubber皮下脂肪组织比海水低的传热系数（thermalconductivity）流经的血液量少脂肪外面可接近环境温度AdaptationsforColdEnvironments隔热Insulation:褐色脂肪在鸟类和许多哺乳类均有发现主要在肩胛骨（scapula）产热迅速中间分布大量的血管和线粒体脂肪细胞自身氧化细胞中有许多脂肪代谢酶UniversityofCaliforniaDavisAdaptationsforColdEnvironments血液流动寒冷时哺乳动物皮下细动脉收缩（Vasoconstrictionofarterioles）核心部位蓄热鲸鱼显得尤为重要依赖于限制体表血流量较大限制血流量=提高隔热层的功能第三节散热与体温调节反应的关系产热量和散热量深部体温与呼吸数环境温度(Te)乳中温度(Tmilk)41403938平均体表温和显热散热Heattransferfromanelephantpinna（大象耳廓）attwoambienttemperatures.深部体温呼吸数和潜热散热量猪和牛的差异平均体表温呼吸数和热流量平均体温和热流量、隔热特性平均体温和散热量、隔热特性PigHuddlingat33.3℃and0.150m/sPigHuddlingat33.3℃and0.363m/sPigHuddlingat29.4℃and0.263m/sPigHuddlingat23.9℃and0.264m/sHeatstresscontrolmeasuresforoutdoorsowsusingshade(遮荫)andwallows（泥浴）.AirTemperatureDryClimateHumidClimateMarginal:lessthan21℃noactionneededaccesstowallowrequiredWarm:2