温热环境对母猪生产性能的影响及其调控技术研究进展

曾雅琼，王浩,2，刘作华，李爽，蒲施桦,2，龙定彪,2



温热环境对母猪生产性能的影响及其调控技术研究进展

曾雅琼1，王浩1,2，刘作华1，李爽1，蒲施桦1,2，龙定彪1,2

（1重庆市畜牧科学院，重庆 402460；2农业部西南设施养殖工程科学观测实验站，重庆 402460）

生猪养殖业是我国农业和农村经济的支柱性产业之一，母猪作为生猪养殖场的核心猪群，其生产性能是决定生猪养殖场经济效益的关键因素。我国是世界生猪养殖的第一大国，能繁母猪存栏量和商品猪出栏量均超过世界总量的50%，然而，与发达国家相比，我国母猪饲养管理水平较低，在生产性能方面仍存在较大差距。实际生产中母猪的生产性能受到诸多因素的影响，主要包括母猪的营养摄取、机体特性、饲养空间环境及胎次等，其中温热环境是影响母猪健康和生产性能的重要因素之一。温热环境包括温度、相对湿度、空气流动、辐射及热传递等因素，他们共同作用于动物，使动物产生冷或热、舒适与否的感觉。适宜的温热环境有利于保障母猪的机体健康，提高其生产性能，反之，不适宜的温热环境会引起母猪的热环境应激，破坏体热平衡，甚至导致生产停止，使机体进入病理状态，引发疾病甚至死亡。因此，掌握母猪的温热环境需求并采取有效的调控措施，对提高母猪生产性能和生猪养殖场经济效益至关重要。文章从温热环境对母猪的影响和温热环境调控技术两个方面进行综述，旨在为我国生猪养殖场母猪生产管理的温热环境调控提供理论依据和技术支撑。（1）温热环境对母猪的影响方面。温热环境对母猪的影响主要体现在行为、生理和生产性能等方面的变化。在行为方面，高温环境下，由于侧卧时母猪体表与地面的接触面积更大，可增加机体散热量，母猪会通过行为姿势改变进行热调节，如增加侧卧时间、减少站立和俯卧时间，而母猪姿势行为的频繁改变会增加仔猪压死率。在生理方面，热应激时母猪会通过减少采食量、增加呼吸率和皮肤血流量等途径来减少代谢产热、增加散热，同时母猪血液中促肾上腺皮质激素和皮质醇会增加、甲状腺素降低、胰岛素敏感性增加，这些生理变化会破坏母猪机体内分泌和能量平衡，进而导致胚胎早期死亡、流产和泌乳量下降。在生产性能方面，热应激会对母猪发情间隔、产仔数和泌乳量等生产性能造成不利影响，妊娠前期热应激主要影响返情率和产仔数，妊娠后期主要影响产活仔数和死胎数，分娩后则主要影响仔猪存活率，环境高温通过影响母猪的泌乳量对哺乳仔猪生产性能产生不利影响，通过影响母猪的采食量、泌乳期母猪失重和体内生殖激素的分泌，导致母猪断奶后发情延迟。（2）温热环境调控技术方面。母猪温热环境调控技术主要包括猪舍整体降温和局部降温两种，整体降温以“湿帘-风机”蒸发冷却降温技术为代表，通过风机排风造成舍内负压，迫使舍外未饱和的空气流经湿润的多孔湿帘，引起水分蒸发吸收大量潜热，降低进入舍内的空气温度，从而达到降低舍内温度的目的，该技术具有设备简单、经济高效的优势。猪舍局部降温主要是针对猪只躺卧区地板、两侧猪栏、猪栏上方等区域进行温度调控，主要有风管喷气嘴蒸发冷却、冷水覆盖降温和猪舍地板降温等方式，具有降温效果良好和节能的优点。

母猪；温热环境；调控；生产性能

我国是世界生猪养殖的第一大国，生产母猪存栏量和商品猪出栏量均超过世界总量的50%[1]，是我国农业和农村经济的支柱性产业之一。母猪作为生猪养殖场的核心猪群，其繁殖性能是决定生猪养殖场经济效益的关键环节。我国的母猪管理水平与发达国家相比还存在较大差距，我国平均每头生产母猪年提供商品肥猪（MSY）不超过15头，年产胎次（LYS）为2.2，而欧洲、加拿大、美国等国家MYS则超过25头，丹麦更是超过30头，LYS则达到2.3—2.4[2]。母猪的生产繁殖性能由营养、机体特性、饲养环境及胎次[3-6]等多种因素共同决定，其中温热环境是重要影响因素之一，适宜的温热环境有利于保障母猪的健康状况，提高其生产和繁殖性能，反之则会引起母猪的热应激，破坏体热平衡，甚至导致生产停止，使机体进入病理状态，引发疾病甚至死亡[7-8]。因此，掌握母猪的温热环境需求并采取有效的调控措施，对提高母猪生产繁殖性能和生猪养殖经济效益至关重要。

本文以母猪为对象，以温热环境为影响因素，通过对国内外相关研究成果的综述、分类和总结，阐述了温热环境对母猪繁殖性能、行为习性和生理状况等的影响，并详细介绍国内外母猪温热环境调控新技术、新方法和新设备，旨在为我国生猪养殖场母猪生产管理的温热环境调控提供理论依据和技术支撑。

1 温热环境对母猪的影响

1.1 生产性能

热应激对养猪业的经济效益影响巨大，其主要表现为母猪生产性能的下降所造成的经济损失。据统计在美国由热应激所导致的母猪经济损失高达4.5亿美元/年[9-10]，而热应激对母猪生产性能产生的不利影响主要体现在产仔数、仔猪成活率、泌乳量、断奶至发情间隔等方面[11-12]，且存在生理阶段差异。

热应激对母猪产仔数的不利影响存在生理阶段差异性：妊娠前期热应激主要影响返情率及产仔数，妊娠后期热应激主要影响产活仔数和死胎数，分娩后热应激则主要影响仔猪存活率。TUMMARUK等[13]认为在妊娠早期（1—35 d）高温应激显著降低产仔数和产活仔数，而妊娠晚期的高温应激（102—110 d）导致死胎率升高[14]。 TANTASUPARUK等[15]认为在妊娠前四周猪舍每日最高温度提高1℃，窝产仔数降低0.07头。BLOEMHOF等估算得出影响产仔数和分娩率的温度上限阈值分别为21.7℃和19.2℃[16]，而我国南方地区夏季猪舍平均温度在29℃以上[17-18]。李延森等[19]报道江苏盐城环境温度对母猪繁殖性能的影响，夏季（7月份）最高气温时，母猪的总产仔数（10.9头）和断奶活仔数最低（7.65头），胎均死胎数最高（0.49），并且温度与返情率呈正相关，与7d发情率呈负相关。WEGNER等[8]研究了温度（15—25℃）对夏季母猪繁殖性能的影响，发现配种前6d至配种后14d期间高温显著降低母猪窝产仔数（＜0.05）；产前4d内的高温环境显著降低活仔数（＜0.05）、提高死胎数（＜0.001），环境温度每升高1℃，窝产仔数减少0.03头；分娩至产后12d，高温环境显著降低仔猪存活率（＜0.05），温度每升高1℃，窝活仔数减少0.02头。

环境高温通过影响母猪的泌乳量对哺乳仔猪生产性能产生不利影响。高温环境下，母猪通过减少采食量和增加体表皮肤的血液流量，达到降低产热、增加散热的目的，从而导致母猪乳腺合成乳汁需要的养分减少，降低母猪的泌乳量[20-22]。

SPENCER等[23]研究发现，与21℃相比，高温环境下（32℃）母猪产后第第14天采食量显著降低（7.97kg vs 4.83kg，＜0.01）、母猪失重显著增加（-1.8kg vs 16.6kg，＜0.01）、泌乳量降低约30%（＜0.01）WILLIAMS等[24]研究发现，与适宜温度环境相比（18—20℃），高温环境（24—30℃）下的哺乳仔猪断奶重显著降低了0.5kg（＜0.05）；PRUNIER等[25]报道，与适宜环境温度（18℃）相比，高温环境（27℃）显著提高了6—21日龄哺乳仔猪的死亡数（0.2头 vs 0.7头，＜0.05），极显著降低母猪哺乳期采食量（6.10kg vs 4.40kg，＜0.001）和仔猪断奶重（6.44kg vs 5.09kg，＜0.001）；SURIYASOMBOON等[26]的研究也证实了断奶前期、配种期和分娩时环境高温高湿会对仔猪产生不利影响。林映才等[27]总结了大量国外高温环境对母猪及仔猪的影响，发现与适温条件相比（18—22℃），热应激（28—32℃）可使泌乳母猪采食量降低40%，泌乳量减少25%，仔猪增重减少20%，体重损失增加2.6倍。

断奶至发情间隔直接影响母猪生产周期及年生产力[28]，热应激通过影响母猪的采食量、泌乳期母猪失重和体内生殖激素的分泌，进而导致母猪断奶后发情延迟。研究指出，有9%的分娩母猪在夏季高温时出现发情延迟现象[29]，且配种率下降，当猪舍环境温度高于23℃时，母猪配种率极显著降低（=0.001）[30]。PRUNIER等[25]研究发现，与适宜环境温度（18℃）相比，高温（27℃）导致母猪断奶后10 d内的发情率显著降低（13/17 vs 7/18，＜0.05）。BOMA等[31]研究表明，随着环境温度的升高，母猪断奶至发情间隔的时间逐渐增加，当平均温度在37.2℃时发情间隔显著高于25.6℃时的发情间隔（12.7 d vs 7.9 d）。高温环境下，母猪断奶至发情间隔增加，发情延迟则母猪空怀期延长，且生产者无法预测或保持仔猪输出量，影响猪场生产力和经济效益[32-33]，因此，有必要在夏季高温时采取措施缓解母猪热应激。

1.2 行为及福利

行为是评价动物适应环境变化的重要指标。热应激时母猪热舒适性较差，会出现哺乳、躺卧姿势、采食等行为变化，降低其福利水平，增加仔猪的压死率[34-35]。高温环境下，母猪会通过行为姿势改变进行热调节，如减少站立时间、增加侧卧时间、减少俯卧时间等，侧卧时母猪体表与地面的接触面积更大，增加了机体传导散热量。MUNS等[36]从分娩前16h至分娩后24h连续测定了母猪的行为，发现两组母猪（20℃和25℃）躺卧、坐和站立行为无显著差异（＞0.05），但躺卧的姿势存在显著差异，与对照组（20℃）相比，热应激环境（25℃）显著提高母猪分娩前16h（47.3% vs 61.5%，=0.003）和分娩后24h（81.6% vs 92.6%，=0.018）侧卧姿势的时间，显著降低母猪分娩前16h（61.3% vs 25.2%，=0.001）和分娩后24h（11.1% vs 3.9%，=0.038）俯卧姿势的时间。高娅俊等[35]研究了高温（30.4℃）和低温（15.3℃）对分娩母猪行为的影响，发现低温组均显著提高母猪站立（10% vs 21.7%）、跪立（0.2% vs 0.4%）、腹卧（14% vs 25%）和臀部下落时间（3.4s vs 4.0s），降低侧卧时间（66.9% vs 42.1%）以及母猪6 h内的坐立-腹卧（4.7 vs 2.2）、腹卧-坐立（4.9 vs 2.5）的转换频次。由于母猪的坐立-腹卧、站立-躺卧行为的转换以及臀部快速下落常常导致仔猪的压死，高温导致仔猪的压死率显著升高（15.2% vs 0），CANADAY等[37]的研究结果与其一致。DEVILLERS和FARMER[34]研究了环境温度对分娩母猪行为的影响，发现与适温环境（21℃）相比，高温（29℃）显著减少哺乳母猪的站立时间（11.4% vs 9.3%，=0.008），缩短哺乳时长（6.2 min vs 5.4min，=0.01），提高哺乳频率（34.4 vs 37.5，＜0.001），这可能是由于高温环境下母猪产奶量下降，仔猪由于饥饿而刺激母猪的哺乳行为。QUINIOU等[38]研究发现高温环境下（29℃）泌乳母猪的采食次数（4.8 vs 7.3）、采食量（3 495g vs 6 423g）、采食时间（29.6min·d-1vs 50.4min·d-1）均比25℃环境显著降低，而饮水量显著提高（7.1l/kg采食量 vs 4.4l/kg采食量），并且高温环境显著降低夜间采食比例（10% vs 23%）。

1.3 生理状况

母猪自身的体热调控能力差，当其处于热应激状态时，会通过减少采食量、增加呼吸率和皮肤血流量等途径来减少代谢产热、增加散热以适应高温环境，但当其直肠温度升高时，上述热调控方式就不能完全补偿热应激带来的不利影响，导致长时间的能量负平衡和母猪机体受损[39]。热应激环境对初产母猪的生理状况影响更为明显，泌乳期的热应激导致初产母猪的直肠温度显著高于经产母猪（39.0℃ vs 38.7℃，＜0.019），这表明高温降低初产母猪能量稳衡的能力，并可能降低代谢能转化为母乳的能力[40-41]。热环境下，母猪体热调节平衡被破坏，交感神经兴奋，显著增加猪只呼吸量，使得呼吸频率增加和深度变浅，呼吸频率可超过40次/min[41-42]，DE OLIVEIRA等[43]报道，与21.0℃相比，25.7℃环境中分娩母猪的呼吸频率显著提高（早上：28.0次/min vs 43.7次/min；下午：33.7次/min vs 61.7次/min），但直肠温度无显著差异。WILLIAMS等[24]报道，分娩栏中处于热应激环境（24—30℃）中的母猪，其直肠温度显著高于（＜0.001）适温环境（18—20℃）中的母猪；热应激环境中母猪的呼吸频率约是适温环境中母猪的2倍。MUNS等[36]的研究发现，与适温环境（20℃）相比，高温环境（25℃）显著提高了母猪产前1 d (=0.033)和分娩当天（=0.004）的呼吸频率；提高了分娩前1d到分娩后8d的直肠温度，并且分娩后1d达到显著水平；分娩3d内的平均乳腺表面温度提高了0.9℃。

肾上腺和甲状腺在维持机体代谢、调节机体稳态中起着重要作用，高温环境可以改变母猪体内激素水平[44]。热应激时，母猪机体通过增加下丘脑促肾上腺皮质激素释放激素，促进促肾上腺皮质激素分泌来对抗热应激，而促肾上腺皮质激素的分泌会抑制促卵泡素和促黄体素的分泌，导致母猪黄体、孕酮不足，出现胚胎早期死亡及流产[45]。MALMKVOST等[46]在母猪产前12h至产后48h给予地板加热处理（33—34℃）发现，与对照组相比，地板加热处理组母猪的皮质醇和促肾上腺皮质激素分别提高了29%(=0.02)和17%(=0.08)。BARB等[47]研究发现，与22℃饲养环境相比，30℃下母猪的甲状腺素水平下降30%，黄体化激素水平不变，但其脉冲频率（＜0.003）和振幅（＜0.03）均显著提高。PRUNIER等[25]的研究结果显示，与20℃相比，30℃热应激环境显著降低母猪血清三碘甲状腺氨酸浓度（＜0.05），提高血糖浓度（＜0.001）。热应激时猪只胰岛素的敏感性增加，免疫系统是潜在的葡萄糖利用者，且免疫系统一旦激活，免疫细胞就会变成葡萄糖利用者，并改变了机体的能量稳衡，因此需要更多的葡萄糖来维持血糖平衡，而与泌乳相关的葡萄糖利用率较低，这也在一定程度上解释了高温引起的泌乳量下降[22, 48-50]。

2 母猪温热环境调控技术

缓解母猪高温热应激是一项系统工作，除了通过猪舍设计与环境建设、合理的饲养管理技术、适宜的保健预防等[51-55]基础措施以外，亦可配合蒸发冷却降温、水冷覆盖降温、地板降温等舍内温度调控技术，使高温环境对母猪生产繁殖性能产生的不利影响最小化。

2.1 猪舍整体降温技术

猪舍整体降温通常采用通风降温、蒸发降温两种方式。通风降温分为自然通风和机械通风，自然通风受气候环境影响显著，在炎热潮湿的南方地区，其降温效率受到限制；机械通风常应用于大型密闭性养猪场，以负压通风为主，但存在通风死角或局部温度过高的区域[56]。蒸发降温包括湿帘风机降温、喷淋降温、喷雾降温等，湿帘风机降温系统由于其设备构造简单、降温速度快、稳定耐用等优势，目前广泛应用于我国大部分密闭式猪舍[57-60]。

湿帘-风机降温系统由特种纸质多孔湿帘、低压大流量轴流风机、水循环系统及控制装置组成，湿帘、风机分别安装在畜禽舍的两端，风机抽风时造成舍内负压，迫使舍外未饱和的空气流经湿润的多孔湿帘，引起水分蒸发吸收大量潜热，降低进入舍内的空气温度，从而达到降低舍内温度的目的。猪由于汗腺不发达，对高温环境更为敏感[61-62]。湿帘-风机蒸发冷却系统可改善暴露于极端热环境中母猪的热舒适性，缓解热应激。DONG等[63]对比了纵向通风、头部垂直通风、水平通风、滴水降温等不同降温组合在分娩母猪舍的应用效果，结果发现纵向通风配合滴水降温是更为有效的降温组合。高增月等[64]就湿帘-风机系统降温和自然通风降温的分娩舍进行了对比试验，结果发现，夏季湿帘风机系统能显著降低舍内温度（27.9℃vs 31.5℃，＜0.05），使哺乳仔猪的断奶成活率提高6.97%。CARLAR等[65]研究了湿帘-风机系统妊娠舍舍内母猪的生产性能及舍内温湿指数，与无降温系统相比，湿帘-风机系统显著降低母猪断奶至发情间隔时间（5.29d vs 4.53d，＜0.05），显著提高断奶时母猪背膘厚（15.55mm vs 17.86mm，＜0.05），显著提高了仔猪初生重（＜0.05），这与Liao等[66]的观点一致；试验期间有降温系统的猪舍舍内温湿指数平均值（77.52）显著低于（＜0.05）无降温系统猪舍（79.67）。该结果与BLOEMHOF等[67]的研究结果一致，表明湿帘-风机降温系统可显著改善舍内温热环境和提高母猪后续的生产性能。KIEFER等[68-69]使用CFD方法对分娩母猪舍湿帘降温系统进行评估，指出该系统在风速、温度和相对湿度等指标的均匀性方面需要进一步优化。

2.2 猪舍局部降温技术

猪舍局部降温主要是针对猪只躺卧区地板、两侧猪栏、猪栏上方等区域进行温度调控。局部降温适用于开放舍和有通风死角的密闭舍，局部小环境温度调控方法设备简单、节能高效、气流容易组织、温控易于实现[18]。常用的猪舍局部降温技术有冷水覆盖地板或猪栏、喷气嘴冷却降温等。

2.2.1 风管喷气嘴蒸发冷却系统 通过组织气流，增加动物活动区风速，是缓解猪只热应激的有效手段之一[70-71]，风管喷气嘴蒸发冷却系统即利用这一方式对猪舍局部降温，以达到缓解母猪热应激的目的。该系统由风管、湿垫、风机及控制系统组成。分娩猪舍一端外墙安装连接着主风管的蒸发冷却垫，经过湿垫的冷空气由轴流风机送入主风管进入舍内，主风管由两个独立的支风管组成，每个支管服务两排分娩栏，每个分娩栏上方有独立的末端喷气嘴使空气到达猪脖颈区域，推荐流量为120m³·h-1[72]，当舍内温度高于20℃时系统自动开启[73]。

PERIN等[73]人研究了传统湿帘温度控制系统（TTCS）和风管喷气嘴蒸发冷却系统（ESCS）对泌乳母猪直肠温度、采食量、失重及其仔猪体重的影响。结果显示，与TTCS组相比，ESCS组母猪直肠温度显著降低（＜0.05），失重显著下降（5.3% vs 2.2%，＜0.05），断奶至发情间隔显著缩短（10.9 d vs 7.0 d，＜0.05），采食量显著增加（4.8 kg·d-1vs 5.8 kg·d-1，＜0.05），窝产仔数显著增加（10.9头vs 12.0头，=0.095），采食量的变化与RENAUDEAU等[74]的研究结果一致，温度通过影响母猪体重间接影响其断奶至发情间隔[75]。JUSTINO等[76]比较了传统机械通风与风管蒸发冷却系统在分娩母猪上的降温效果，结果发现，与传统机械通风降温相比，风管蒸发冷却降温可使母猪头部上方区域干球温度降低2.09℃（＜0.05），母猪体表温度降低0.47℃（＜0.05），呼吸频率降低25.4%（＜0.05）。相比于传统温度控制系统，风管蒸发冷却系统的使用对于增加母猪热损耗作用显著，能缓解高温对母猪体温调节的负面影响，使母猪采食量显著提高、体重损失减少、繁殖性能提高，母猪和仔猪生产性能均明显改善。

2.2.2 冷水覆盖降温 冷水覆盖降温是在猪栏上方及侧面铺设冷水管，通过热传导及辐射作用，使猪栏相邻单元达到适宜的温度环境。PANG等[77-78]研发了一套冷水覆盖降温系统（WCCs），并探究了该系统对高温高湿气候下分娩母猪生理和生产性能参数的影响。WCCs由钢结构框架、镀锌钢制水管和铝制遮蓬组成，水管沿长度方向安装于拱形顶内侧，两端为2根竖直水管（其中相邻单元间共用1根竖直管），3单元为一组，进出水口分别位于该组WCC两侧，拱顶上部覆盖聚乙烯泡沫隔热。研究结果显示，当舍内环境温度为37℃时，系统可以将母猪躺卧区温度降低3.0—4.5℃，在舍内温度小于35℃时保持适宜的温度范围（25—30℃）；当环境温度低于30℃时，分娩母猪的呼吸频率和体表温度在处理组（WCCs）和对照组（洒水冷却）之间无显着差异，但当温度升高到30℃以上时差异显著（＜0.05）；对照组母猪在炎热天气时饮水量较多，但采食量显著少于处理组的母猪（＜0.01）。室内空气温度为34.3℃时，在WCCs的作用下，母猪躺卧区的黑球温度在有母猪和无母猪的情况下分别可降温4.8℃和5.4℃；母猪躺卧区的温降幅度与系统进出水温度差成正比，在一定范围内增加水流速度可提高降温效率[79]。李伟等[80]研究了冷水覆盖降温对母猪躺卧行为的影响，结果发现，当猪舍温度大于31℃时，75%的母猪选择在冷水覆盖猪床内躺卧，且该比例随着环境温度升高而增加。因此，水冷覆盖降温系统的使用可以减轻典型炎热气候期间分娩母猪的热应激，具有提高母猪生产性能的实用价值。

2.2.3 猪舍地板局部降温 猪舍地板局部降温是指以地下水或压缩冷却水为媒介、在猪的躺卧区地板下部铺设水管的一种传导降温方式。据报道，猪只一天中有79%的时间（约19 h）都在休息，这意味着大部分猪只的身体长时间与地面接触[81]，因此，高温季节采取地板降温是一种有效缓解猪只热应激的方式。李保明[82]等研发了一种利用地下水对猪舍地板局部降温的技术，试验发现环境温度34℃时该技术可将母猪躺卧区域温度控制在22—26℃，与SHI等的结果一致[83]。BARBARI等[84]发现在高温季节母猪同时使用地板降温和气流降温更为舒适。SILVA等[85-86]研究发现，采用地板降温（地板温度27.6℃）母猪的采食量（6.47kg·d-1vs 5.61kg·d-1，＜0.01）、断奶时仔猪体重（6.42kg/头 vs 5.30 kg/头）显著高于对照组（地板温度35.8℃）；地板降温组母猪的直肠温度、体表温度和呼吸率均更低（＜0.01），侧卧时间更短（＜0.01）、哺乳时间更长（＜0.05）、采食时间更长（＜0.01）。CABEZON等[87-88]初步评估了降温地板的3种水流速度（0.25、0.55和0.85 L·min-1）对高温环境下（环境温度35.3℃，相对湿度57.8%）分娩母猪的影响，高水流速度（0.85 L·min-1）时，分娩母猪各项指标最佳（呼吸率为31，直肠温度为39.1℃，散热率为320.7w）。地板降温方式可增加哺乳母猪的日采食量，减少失重，缩短断奶至发情间隔，同时可改善母猪哺乳行为，增加泌乳量。

3 结语

母猪作为生猪养殖场的核心猪群，适宜温热环境的控制至关重要，这有利于保障母猪健康状况，从而提高其生产和繁殖性能。蒸发冷却降温、水冷覆盖降温、地板降温等温热环境调控技术，在实际生产中，除了湿帘-风机蒸发降温系统在规模猪场中利用率较高，其余几种技术虽然降温效果明显、运行能耗低，但受成本、管理等因素限制，尚未被推广应用，还有待进一步结合实际进行优化应用。本文所述母猪温热环境调控技术仅为该领域内典型部分，以期为我国生猪养殖场母猪温热环境调控实施提供参考。

[1] 张晓东. 中国养猪业生产波动分析与预测预警研究[D]. 哈尔滨: 东北农业大学, 2013.

ZHANG X D. The Study on the production fluctuation analysis, forecasting and warning for the pig industry in China[D]. Harbin: Northeast Agricultural University, 2013. (in Chinese)

[2] 孙海清. 母猪妊娠日粮中可溶性纤维调控泌乳期采食量的机制及改善母猪繁殖性能的作用[D]. 武汉: 华中农业大学, 2013.

SUN H Q. Mechanism of soluble fiber inclusion in gestation diets regulating lactation feed intake of sows and its role in improving reproductive performance of sows[D]. Wuhan: Huazhong Agricultural University, 2013. (in Chinese)

[3] WHITTAKER A L, PLUSH K J, TERRY R, HUGHES P E, KENNAWAY, D J, VAN W, WILLIAM H E J. Effects of space allocation and parity on selected physiological and behavioral measures of well-being and reproductive performance in group-housed gestating sows., 2015, 176: 161-165.

[4] VAN WETTERE W H E J, PAIN S J, HUGHES P E. Dietary ractopamine supplementation during the first lactation affects milk composition, piglet growth and sow reproductive performance., 2016, 174: 87-92.

[5] FAN Z Y, YANG X J, KIM J, MENON D, BAIDOO S K. Effects of dietary tryptophan: lysine ratio on the reproductive performance of primiparous and multiparous lactating sows., 2016, 170: 128-134.

[6] REMPEL L A, VALLET J L, LENTS C A, NONNEMAN D J. Measurements of body composition during late gestation and lactation in first and second parity sows and its relationship to piglet production and post-weaning reproductive performance., 2015, 178: 289-295.

[7] CABEZON F A, SCHINCKEL A P, MARCHANT-FORDE J N, JOHNSON J S, STWALLEY R M. Effect of floor cooling on late lactation sows under acute heat stress., 2017.

[8] WEGNER K, LAMBERTZ C, DAS G, REINER G, GAULY M. Effects of temperature and temperature‐humidity index on the reproductive performance of sows during summer months under a temperate climate., 2016, 87(11):1334-1339.

[9] POLLMAN D. Seasonal Effects On Sow Herds: Industry Experience and Management Strategies., 2010, 88(Suppl. 3): 9.

[10] ST-PIERRE N R, COBANOV B, SCHNITKEY G. Economic Losses from heat stress by US livestock industries., 2003, 86 (1S): 52-77.

[11] PELTONIEMI O A T, TAST A, LOVE R J. Factors effecting reproduction in the pig: Seasonal effects and restricted feeding of the pregnant gilt and sow., 2000, 60-61 (Suppl. C): 173-184.

[12] VON BORELL E, DOBSON H, PRUNIER A. Stress, behavior and reproductive performance in female cattle and pigs., 2007, 52 (1): 130-138.

[13] TUMMARUK P, TANTASUPARUK W, TECHAKUMPHU M, KUNAVONGKRIT A. Effect of season and outdoor climate on litter size at birth in purebred landrace and yorkshire sows in thailand., 2004, 66(5): 477-482.

[14] OMTVEDT I T, NELSON R. E, EDWARDS R. L,STEPHENS D F, TURMAN E J. Influence of Heat Stress During Early, Mid and Late Pregnancy of Gilts., 1971, 32: 312-317.

[15] TANTASUPARUK W, LUNDEHEIM N, DALIN A M,KUNAVONGKRIT A, EINARSSON S. reproductive performance of purebred landrace and yorkshire sows in thailand with special reference to seasonal influence and parity number., 2000, 54: 481-496.

[16] BLOEMHOF S, MATHUR P K, KNOL E F, VAN DER WAAIJ H E. Effect of daily environmental temperature on farrowing rate and total born in dam line sows., 2013, 91: 2667-2679.

[17] 杨润泉, 方热军, 杨飞云, 黄金秀, 刘虎, 周水岳, 周晓蓉, 王浩. 环境温湿度和猪舍空气质量对妊娠母猪生产性能的影响. 家畜生态学报, 2016(12):40-43.

YANG R Q, FANG R J, YANG F Y, HUANG J X, LIU H, ZHOU S Y, ZHOU X R, WANG H. Effect of environmental temperature, humidity, and air quality on performance of pregnant sows., 2016(12):40-43. (in Chinese)

[18] 乔克. 重庆地区半开放式猪舍夏季降温措施研究[D], 重庆: 西南大学, 2006.

QIAO K. Study on summer cooling measures of semi - enclosed pig house in Chongqing[D]. Chongqing: Southwest University, 2006. (in Chinese)

[19] 李延森, 沈祥星, 李春梅. 母猪发情和产仔性能与环境温度变化相关性分析. 畜牧兽医学报, 2016(6):1133-1139.

LI Y S, SHEN X X, LI C M. Correlation Analysis between the ambient temperatures and reproductive performance of sows., 2016(6):1133-1139. (in Chinese)

[20] EISSEN J J, APELDORN E J, KANIS E, VERSTEGEN M W A, GREEF DE K H. The Importance of a high feed intake during lactation of primiparous sows nursing large litters., 2003, 81(3): 594-603.

[21] EISSEN J J, KANIS E, KEMP B. Sow factors affecting voluntary feed intake during lactation., 2000, 64(2): 147-165.

[22] LUCY M C, SAFRANSKI T J. Heat stress in pregnant sows: Thermal responses and subsequent performance of sows and their offspring., 2017, 84(9): 946-956.

[23] SPENCER J D, BOYD R D, CABRERA R, ALLEE G L. Early weaning to reduce tissue mobilization in lactating sows and milk supplementation to enhance pigs weaning., 2003, 81: 2041-2052.

[24] WILLIAMS A M, SAFRANSKI D E, EICHEN P A, COATE E A, LUCY M C. Effects of a controlled heat stress during late gestation, lactation, and after weaning on thermoregulation, metabolism, and reproduction of primiparous sows., 2013, 91: 2100-2714.

[25] PRUNIER A, DE BRAGANCA M M, LE DIVIDICH J. Influence of high ambient temperature on performance reproductive sows., 1997, 52(2): 123-133.

[26] SURIYASOMBOON A, LUNDEHEIM N, KUNAVONGKRIT A,EINARSSON S. Effect of temperature and humidity on reproductive performance of crossbred sows in Thailand., 2006, 65(3): 606-628.

[27] 林映才, 马现永. 热应激对母猪生产的影响与技术对策. 中国畜牧兽医学会养猪分会2006年学术年会暨第四次全国会员代表大会. 天津: 2006, 284-291.

LIN Y C, MA X Y. Effects of heat stress on sow production and technical countermeasures. Chinese Association of Animal Science and Veterinary Medicine of Pigs Branch 2006 Annual Meeting and the Fourth National Membership Congress. Tianjin: 2006, 284-291. (in Chinese)

[28] 蒲红州, 沈林園, 蒋小兵, 高菲, 雷怀刚, 朱砺. 断奶至发情间隔天数对母猪年生产力的影响. 猪业科学, 2013(6):110-112.

PU H Z, SHEN L Y, JIANG X B, GAO F, LEI H G, ZHU L. Effects of wean-to-estrus intervals on annual productivity of sows., 2013(6):110-112. (in Chinese)

[29] KOKETSU Y, DIAL G D, KING V L. Returns to service after mating and removal of sows for reproductive reasons from commercial swine farms., 1997, 47 (7): 1347-1363.

[30] 程绍明, 楼华梁, 崔绍荣. 不同环境温度对母猪发情行为的影响. 家畜生态, 2004, 25(4):60-62.

CHENG S M, LOU H L, CUI S R. Oestrus behavior of sows under different environment., 2004, 25(4):60-62. (in Chinese)

[31] BOMA M H, BIIKEI G. Seasonal infertility in Kenyan pig breeding units : research communication., 2006, 73: 229-232.

[32] BERTOLDO M, GRUPEN C G, THOMSON P C, EVANS, G, HOLYOAKE P K. Identification of sow-specific risk factors for late pregnancy loss during the seasonal infertility period in pigs., 2009, 72 (3): 393-400.

[33] IIDA R, KOKETSU Y. Interactions between climatic and production factors on returns of female pigs to service during summer in japanese commercial breeding herds., 2013, 80 (5): 487-493.

[34] DEVILLERS N, FAARMER C. Effects of a new housing system and temperature on sow behaviour during lactation., 2008, 58 (1): 55-60.

[35] 高娅俊, 李保明, 李明丽, 林保忠, 顾招兵. 舍温对母猪行为与仔猪保温箱利用率的影响. 农业工程学报, 2011(12):191-194.

GAO Y J, LI B M, LI M L, LIN B Z, GU Z B. Impacts of room temperature on sow behavior and creep box usage for pre-weaning piglet., 2011(12):191-194. (in Chinese)

[36] MUNS R, MALMKVIST J, LARSEN M L, SORENSEN D, PEDERSEN L J. High environmental temperature around farrowing induced heat stress in crated sows., 2016, 94(1): 377-384.

[37] CANADAY D C, SALAK-JOHNSON J L, VISCONTI A M, WANG X, BHALERAO K, KNOX R V. Effect of variability in lighting and temperature environments for mature gilts housed in gestation crates on measures of reproduction and animal well-being., 2013, 91: 1225-1236.

[38] QUINIOU N, RENAUDEAU D, DUBOIS S, NOBLET J. Effect of diurnally fluctuating high ambient temperatures on performance and feeding behaviour of multiparous lactating sows., 2000, 71 (3): 571-575.

[39] QUINIOU N, NOBLET J. Influence of high ambient temperatures on performance of multiparous lactating sows., 1999, 77: 2124-2134.

[40] GOURDINE J L, BIDANEL J. P, NOBLET J, RENAUDEAU D. Rectal temperature of lactating sows in a tropical humid climate according to breed, parity and season., 2007, 20 (6): 832-841.

[41] MARTIN W R. Effects of heat stress on thermoregulation, reproduction and performance of different parity sows[D]. New York: Columbia: University of Missouri, 2012.

[42] HUYNH T T, AARNINK A J, VERSTEGEN M W, GERRITS W J, HEETKAMP M J, KEMP B, CANH T T. Effects of increasing temperatures on physiological changes in pigs at different relative humidities., 2005, 83 (6): 1385-1396.

[43] DE OLIVEIRA JUNIOR G M, FERREIRA A S, OLIVEIRA R F M, SILVA B A N, DE FIGUEIREDO E M, SANTOS M. Behavior and performance of lactating sows housed in different types of farrowing rooms during summer., 2011, 141(2-3): 194-201.

[44] 程远芳, 宋代军, 曾有权, 张家骅. 中草药添加剂对生长猪抗热应激机理研究. 动物营养学报, 2006, 18(1):43-48.

CHENG Y F, SONG D J, ZENG Y Q, ZHANG J H. Studies on the mechanism of herb additive on alleviating heat stress of growing pigs., 2006, 18(1):43-48. (in Chinese)

[45] 陈丽, 张彬, 李丽立. 热应激对母猪繁殖性能的影响及防治措施. 饲料博览, 2015(9):13-17.

CHEN L, ZHANG B, LI L L. The Effects of heat stress on reproductive performance of sow and control measures., 2015(9):13-17. (in Chinese)

[46] MALMKVIST J, DAMGAARD B M,PEDERSEN L J, JΦRGENSEN E, THODBERG K, CHALOUPKOVA H BRUCKMAIER R M. Effects of thermal environment on hypothalamic-pituitary-adrenal axis hormones., 2009, 87 (9): 2796-2805.

[47] BARB C R, ESTIENNE M J, KRAELING R R, MARPLE D N, RAMPACEK G B, RAHE C H, SARTIN J L. Endocrine changes in sows exposed to elevated ambient temperature during lactation., 1991, 8(1): 117-127.

[48] BOSS J W, HALE B J, GABLER N K, RHOADS R P, KEATING A F, BAUMGARD L H. Physiological consequences of heat stress in pigs., 2015, 55: 1381-1390.

[49] BAUMGARD L H, RHOADS R P. Effects of heat stress on postabsorptive metabolism and energetics., 2013, 1: 311-337.

[50] VICTORIA S F M, JOHNSON J S, ABUAJAMIEH M, STOAKES S K, SEIBERT J T, COX L, KAHL S, ELSASSER T H, ROSS J W, ISOM S C, RHOADS R P, BAUMGARD L H. Effects of heat stress on carbohydrate and lipid metabolism in growing pigs., 2015, 3 (2): e12315.

[51] 邱进杰, 朱黎. 夏季母猪热应激及应对措施. 畜禽业, 2016(9): 20-21.

QIU J J, ZHU L. Heat stress and control measures of sow in summer., 2016(9):20-21. (in Chinese)

[52] 邹兴汶. 夏季母猪热应激的危害及应对措施. 福建畜牧兽医, 2016, 38(5):42-43.

ZOU X W. Harmfulness of heat stress on sows and control measures in summer., 2016, 38(5):42-43. (in Chinese)

[53] DONG H, ZHONG Y G, LIU F H, YANG K, YU J, XU J Q. Regulating effects and mechanisms of chinese medicine decoction on growth and gut hormone expression in heat stressed pigs., 2012, 143 (1): 77-84.

[54] 雷明刚, 王金勇, 夏伟, 闫之春，孟庆利，华坚青，林家勇，林万清. 传统猪舍改造工艺与新式环境调控猪舍设计及应用. 中国畜牧杂志, 2015 (12): 50-54.

LEI M G, WANG J Y, XIA W, YAN Z C, MENG Q L, HUA J Q, LIN J Y, LIN W Q. Remodeling and improvement of conventional hog production facilities and planning a climate regulated hog farms., 2015 (12): 50-54. (in Chinese)

[55] 曹保山, 罗小锁, 陈忠. 喷雾系统在半开放猪舍夏季降温中应用——基于重庆地区. 农机化研究, 2014 (2):24-27.

CAO B S, LUO X S, CHEN Z. The design and application of spraying air cooling system for semi-enclosed livestock houses— based on chongqing region., 2014 (2):24-27. (in Chinese)

[56] 汪桂英. 夏季猪舍降温措施. 畜禽业, 2016(9):18-19.

WANG G Y. Measures for cooling the pig house in summer., 2016(9):18-19. (in Chinese)

[57] 李少宁, 何贝贝, 宋春阳. 国内规模猪场猪舍降温系统的应用现状. 猪业科学, 2016(6):90-91.

LI S N, HE B B, SONG C Y. Application status of pig house cooling system in domestic scale pig farm., 2016(6): 90-91. (in Chinese)

[58] 付仕伦, 谢宝元. 夏季猪舍降温控制系统应用现状. 农业科学研究, 2007, 28(3):41-44.

FU S L, XIE B Y. Application study of control technique to lower the temperature for pigsty in summer., 2007, 28(3):41-44. (in Chinese)

[59] HUYNH T T T, AARNINK A J A, TRUONG C T, KEMP B, VERSTEGEN M W A. Effects of tropical climate and water cooling methods on growing pigs' responses., 2006, 104 (3): 278-291.

[60] 王美芝, 田见晖, 刘继军, 吴中红, 张瑜. 北京市繁殖猪舍高温环境控制状况. 农业工程学报, 2011 (10):222-227.

WANG M Z, TIAN J H, LIU J J, WU Z H, ZHANG Y. Environment control status of high temperature in reproductive piggery in Beijing., 2011 (10):222-227. (in Chinese)

[61] NANNONI E, WIDOWSKI T, TORREY S, FOX J, ROCHA L M, GONYOU H, WESCHENFELDER A V, GROWE T, MARTELLI G, FAUCITANO L. Water sprinkling market pigs in a stationary trailer. 2. effects on selected exsanguination blood parameters and carcass and meat quality variation., 2014, 160 (Suppl. C): 124-131.

[62] FOX J, WIDOWSKI T, TORREY S, NANNONI E,BERGERON R, GONYOU H W, BROWN J A, CROWE T, MAINAU E, FAUCITANO L. Water sprinkling market pigs in a stationary trailer. 1. effects on pig behaviour, gastrointestinal tract temperature and trailer micro-climate., 2014, 160 (Suppl. C): 113-123.

[63] DONG H M, TAO X P, LI Y, LIU J T, XIN H W. Comparative evaluation of cooling systems for farrowing sows., 2001, 17(1): 91.

[64] 高增月, 卢朝义, 赵书广. 猪舍温度控制技术应用的研究. 农业工程学报, 2006 (S2): 75-78.

GAO Z Y, LU C Y, ZHAO S G. Research on temperature control technique in pig barns., 2006(S2): 75-78. (in Chinese)

[65] CARLAR A A L, LANCE C L P, PANLINE J C, VEGA R S A. Comparative performance of sows housed with and without evaporative cooling system at temperature humidity index of 73-83., 2016, 42(2): 77-84.

[66] LIAO C W. Research of the relief of heat stress on the reproductive performance of breeding pigs-a preliminary report. 2006: Tainan, Taiwan, Republic of China.

[67] BLOEMHOF S, MATHUR P K, KNOL E F, VAN DER EAAIJ E H. Effect of daily environmental temperature on farrowing rate and total born in dam line sows., 2013, 91 (6): 2667-2679.

[68] KIEFER C, MARTINS L P, FANTINI C C. Evaporative cooling for lactating sows under high ambient temperature., 2012, 41 (5): 1180-1185.

[69] WANG K, WANG X, Wu B. Assessment of hygrothermal conditions in a farrowing room with a wet-pad cooling system based on cfd simulation., 57 (5): 1493-1500.

[70] LI H, RONG L, ZHANG G. Numerical study on the convective heat transfer of fattening pig in groups in a mechanical ventilated pig house., 2017. DOI: 10.1016/j. compag.2017.08.013

[71] MASSABIE P, GRAINER R. Effect of air movement and ambient temperature on the zootechnical performance and behaviour of growing-finishing pigs. 94th ASAE Annual International Meeting, 2001: Sacramento CA USA

[72] MATTEO B, MARTINA B, FRANCESCO S G. Preliminary analysis of different cooling systems of sows in farrowing room., 2012, 38 (1): 53-58.

[73] PERIN J, GAGGINI T S, MANICA S, MAGNABOSCO D, BERNARDI M L, WENTZ I, BORTOLOZZO F P. Evaporative snout cooling system on the performance of lactating sows and their litters in a subtropical region., 2016, 46(2): 342-347.

[74] RENAUDEAU D, NOBLET J, DOURMAD J Y. Effect of Ambient Temperature On Mammary Gland Metabolism in Lactating Sows., 2003, 81: 217-231.

[75] HOVING L L, SOEDE N M, FEITSMA H, KEMP B. Lactation weight loss in primiparous sows: consequences for embryo survival and progesterone and relations with metabolic profiles., 2012, 47 (6): 1009-1016.

[76] JUSTINO E, DE A. NÄÄS I, CARVALHO T M R, NEVES D P, SALGADO D D. The impact of evaporative cooling on the thermoregulation and sensible heat loss of sows during farrowing., 2014, 34(6): 1050-1061.

[77] PANG Z Z, LI B M, ZHENG W C, LIN B Z, LIU Z H. Effects of water-cooled cover on physiological and production parameters of farrowing sows under hot and humid climates., 2016, 9(4) :178.

[78] PANG Z Z, LI B M, XIN H W, YUAN X Y, WANG C Y. Characterisation of an experimental water-cooled cover for sows., 2010, 105 (4): 439-447.

[79] PANG Z Z, Li B M, Xin H W, XI L, CAO W, WANG C Y, LI W. Field evaluation of a water-cooled cover for cooling sows in hot and humid climates., 2011, 110(4): 413-420.

[80] 李伟, 李保明, 施正香, 颜志辉, 王朝元, 庞真真. 夏季水冷式猪床的降温效果及其对母猪躺卧行为的影响. 农业工程学报, 2011, 27(11): 242-246.

LI W, LI B M, SHI Z X, YAN Z H, WANG C Y, PANG Z Z. Cooling effect of water-cooled cover on lying behavior of sows in summer., 2011, 27(11): 242-246. (in Chinese)

[81] HUYNH T T T, AARNINK A J A, SPOOLDER H A M, VERSTEGEN M W A, KEMP B. Effects of floor cooling during high ambient temperatures on the lying behavior and productivity of growing finishing pigs., 2004, 47 (5): 1773-1782.

[82] 李保明, 施正香, 张晓颖, 周道雷. 利用地下水对猪舍地板局部降温效果研究. 农业工程学报, 2004, 20(1): 255-258.

LI B M, SHI Z X, ZHANG X Y, ZHOU D L. Effects of cooling floor for pig house using underground water., 2004, 20(1): 255-258. (in Chinese)

[83] SHI Z, LI B, ZHANG X, WANG C, ZHOU D, ZHANG G. Using floor cooling as an approach to improve the thermal environment in the sleeping area in an open pig house., 2006, 93(3): 359-364.

[84] BARBARI M, CONTI L. Use of different cooling systems by pregnant sows in experimental pen., 2009, 103(2): 239-244.

[85] SILVA B A N, OLIVEIRA R F M, DONZELE J L, FERNANDES H C, ABREU M L T, NOBLET J, NUNES C G V. Effect of floor cooling on performance of lactating sows during summer., 2006, 105(1-3): 176-184.

[86] SILVA B A N, OLIVEIRA R F M, DONZELE J L, FERNANDES H C, LIMA A L, RENAUDEAU D, NOBLET J. Effect of floor cooling and dietary amino acids content on performance and behaviour of lactating primiparous sows during summer., 2009, 120 (1-2): 25-34.

[87] SMITH A J, CABEZON F A, SCHINCKEL A P, MARCHANT- FORDE J N, JOHNSON J S, STWALLEY R M. 379 Initial evaluation of floor cooling on lactating sows under acute heat stress., 2017, 95 (suppl. 2): 183-184.

[88] CABEZON F A, SCHINCKEL A P, STEWART K R, RICHERT B T, FANDARILLAS M, MARCHANT-FORDE J N, JOHNSON J S, PERALTA W A, STWALLEY R M. 243 Young scholar presentation: heat stress alleviation in lactating sows by dietary betaine supplementation and cooling pads., 2017, 95 (suppl. 2): 116-117.

（责任编辑 林鉴非）

Effects of Ambient Temperature on Production Performance of Sows and Regulatory Techniques

ZENG YaQiong1, WANG Hao1,2, LIU ZuoHua1, LI Shuang1, PU ShiHua1,2, LONG DingBiao1,2

(1;2Ministry of Agriculture Southwest facility aquaculture engineering scientific observation experimental station, Chongqing 402460)

The pig industry is one of the mainstay industries of China's agriculture and rural economy. As the core component of pig farms, production performance of sows are the key factors for determining the economic benefits of pig farms. China is the largest pig breeding country in the world, and the number of breeding sows and commercial pigs are more than 50% of the world’s total. However, compared with developed countries, sows feeding management level is low in our country, and there is still a large gap in production performance. The performance of sows in practical production is affected by many factors, including nutrient intake, body characteristics, feeding environment, parity of sows, etc. Thermal environment is one of the major factors affecting the health and production performance of sows. The warm environment consists of temperature, relative humidity, air flow, radiation, and heat transfer. These factors work together on the animal to make them feel cold or hot and comfortable or not. The suitable thermal environment is conducive to ensuring the sows’ health and improving their production performance. Conversely, the unsuitable warm environment will cause heat stress in sows, destroy the body heat balance, and even lead production stop, make the body enters a pathological state, cause illness and ultimately death. Therefore, mastering the warm environment requirements of sows and adopting effective control measures are essential to improve the performance of sows and the economic benefits of pig farms.This paper reviewed the effects of warm environment on sows and the corresponding regulation techniques, aiming to provide theoretical basis and technical support for the regulation of thermal environment in pig production and management in China. (1) The effects of the warm environment on the sow are mainly reflected in changes of behavior, physiology and production performance. In terms of behavior, sows will be thermally adjusted by changing the behavioral posture, such as increasing the lying time, reducing the standing and prone time in hot environment. Because the contact area of the sows' body surface with the ground is larger when the side is lying, and the heat dissipation of the body can be increased, but frequent changes in sows’ posture will increase the piglet death rate. In the aspect of physiology, sows will reduce metabolic heat production and increase heat dissipation by reducing feed intake, increasing respiration rate and skin blood flow during heat stress, while promoting the adrenocorticotropic hormone and cortisol in the blood of sows, thyroxine dropped and insulin sensitivity increased. These physiological changes will destroy the endocrine and energy balance of the sow, leading to early embryo death, miscarriage and milk production reduction. In terms of production performance, heat stress adversely affects the performance of sow estrus interval, litter size and lactation. Heat stress mainly affects the re-service rate and litter size at pre-pregnancy and in late pregnancy mainly affects the number of live births and stillbirths. After parturition, heat stress mainly affects the survival rate of piglets. High ambient temperature adversely affects the performance of weaned piglets by affecting the lactation of sows, and heat stress can delay the weaning-to-estrus interval by affecting the feed intake, weight loss and hormone secretion of sows. (2) Thermal environment control technology of sows mainly includes overall cooling and partial cooling of the pig house. The Pad and Fan evaporative cooling system is the representative of the overall cooling of pig house. In the system, the negative pressure inside the house is caused by the exhaust of the fan, forcing the unsaturated air outside the house to flow through the wet porous curtain, causing the evaporation of water to absorb a large amount of latent heat, thereby reducing the temperature inside pig house. The system has the advantages of simplicity and cost-effectiveness. The local cooling of the pig house is mainly for the temperature control of the lying area floor, pig pens on both sides and upper part of the pig pens. The main methods include air duct evaporative cooling, cold water cover cooling, floor cooling, etc. These methods have the advantages of obvious cooling effect and energy saving.

sows; ambient temperature; regulation; performance

2018-04-10；

2018-07-17

“十三五”国家重点研发计划（2016YFD0500500）、现代农业产业技术体系建设专项资金（CARS-35）、重庆市科研院所绩效激励引导专项（17422）

曾雅琼，E-mail：zengyaqionghai@163.com。

蒲施桦，E-mail：opertion5@163.com。通信作者龙定彪，E-mail：longjuan880@163.com