摘要
夏季高温严重影响母猪生产性能,为缓解空怀妊娠母猪夏季热应激,该文采用湿帘冷风机-纤维风管通风系统,以风管定点送风、开孔喷射出风的模式,将冷风输送至妊娠猪活动区域进行局部降温试验,对照猪舍采用自然通风模式。试验结果表明:在舍外日平均最高气温39.9℃,平均温度31.5℃、湿度85.6%时,试验舍和对照舍日平均温度、日平均最高温度分别为27.7、29.6和30.2、32.5℃(P<0.01),湿度分别为87.5%和82.5%(P>0.05);试验舍风管纵向开孔出口平均风速为7.23 m/s,风管下风速从高往低逐渐衰减,母猪活动区域风速为0.99 m/s,对照舍风速为0.16 m/s(P<0.01)。试验舍和对照舍CO2浓度分别为1 849和2 444 mg/m3(P<0.05),NH3浓度分别为1.48和4.96 mg/m3(P<0.01)。试验舍和对照舍平均温湿度指数分别为70.4和73.6(P<0.01),有效环境温度分别为12.1和19.5℃(P<0.01),试验舍全天均处于舒适范围。母猪平均皮温分别为33.3和34.1℃(P<0.05),呼吸频率分别为72.3和87.5次/min(P<0.05)。从生产性能来看,试验舍和对照舍6~9月母猪采食量分别为81.0和72.0 kg/(头·月),试验舍显著高于对照舍(P<0.05),7~11月试验舍和对照舍母猪分娩率分别为89.3%和78.9%,窝产活仔数分别为12.6和11.7头/窝,出生窝质量分别为18.0和17.1 kg/窝,以上指标均差异显著(P<0.05)。结果表明,湿帘冷风机-纤维风管系统的局部降温和风冷效果好,可有效改善舍内热环境,缓解母猪热应激。
Heat stress caused by high temperature has serious adverse effect on the reproduction performance of breeding and gestation sows,so effective cooling in the sow barn is particularly important in summer.In order to improve the indoor thermal environment of breeding and gestation sows,the wet curtain cooling fan-fabric duct ventilation systems were fitted in experiment barn and their cooling effects were evaluated in this study.Cooled fresh air was delivered with fabric duct and was jetted out to sows’movement area from openings along the fabric duct to achieve local cooling.Six wet curtain cooling fans were installed on the experiment barn with 4 on the west wall and 2 on the east wall,and the fabric duct 700 mm in diameter with 1 row ofΦ22 mm openings on the bottom and 2 rows ofΦ26 mm openings on both lower side along the duct was matched based on airflow requirements.The fabric duct was hovered over the sow pen with bottom height of 1.5 m and jet range of 1.5 m wide.Same size barn with natural ventilation was used as control.The results showed that the daily average air temperature in the experiment and control barn were 27.7℃(range from 26.4 to 29.6℃)and 30.2℃(range from 28.4 to 32.5℃)(P<0.01),and the air relative humidity was 87.5%and 82.5%respectively(P>0.05),when the ambient average daily air temperature was 31.5℃(range from 26.5 to 39.9℃)and the average relative humidity was 85.6%.The fan efficiency was 68.2%.The average wind speed at the longitudinal outlets of the air duct was 7.23 m/s and was 0.99 m/s in the sows’movement areas(directly below the air duct and 0.6 m above the floor),meanwhile it was 0.16 m/s in the same area in the control barn(P<0.01).Around the air jet zone,the wind speed was higher in the center than in two sides and attenuated gradually as the height decreased.The air speed from the outlets was 7.23 m/s at height of 1.5 m and decreased to 1.20 m/s,0.93 m/s and 0.58 m/s at heights of 1.2 m,0.8 m and 0.4 m respectively in the jet zone.The average concentrations of CO2 and NH3 in the experiment barn were lower than in control barn(1 849 and 1.48 mg/m3 vs.2 444 and 4.96 mg/m3,P<0.05).The daily average temperature-humidity index(THI)was 70.4 in the experiment barn and was 73.6 in control barn(P<0.01).The thermal environment based on THI was in comfort zone all day in the experiment barn,while it was in alert zone from 10:00 to 18:00 in the control barn.The average effective environmental temperature(EET)was 12.1℃in the experiment barn,which means in the comfort zone all day,while the average EET was 19.5℃in the control barn,which means in the range of heat stress(P<0.01).Correspondingly,the skin temperatures of sows were 33.3 and 34.1℃(P<0.05),and the respiratory rates were 72.3 and 87.5 beats/min in experiment and control barn,respectively(P<0.05).As for the reproduction performance of the whole pig farm,the average delivery rates from July to November were 89.3%and 78.9%,respectively,and the litter size were 12.6 and 11.7 heads/litter with an average litter weight of 18.0 and 17.1 kg/litter in experiment barn and control barn,respectively(P<0.05).No significant difference was found in average estrus and the gestation rate from June to September between experiment barn and no control barn(P>0.05).In conclusion,this study shows that the wet curtain fan-fabric duct ventilation system had good cooling and wind chill effect,which could effectively improve the thermal environment and relieve sows’heat stress.
作者
吴中红
陈泽鹏
臧建军
王美芝
杨皓
任方杰
刘继军
冯广军
Wu Zhonghong;Chen Zepeng;Zang Jianjun;Wang Meizhi;Yang Hao;Ren Fangjie;Liu Jijun;Feng Guangjun(College of Animal Science and Technology,China Agricultural University,Beijing 100193,China;State Key Laboratory of Animal Nutrition,Beijing 100193,China;Qingdao LiangMo Agricultural science and technology Co.,Ltd,Qingdao 266000,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2018年第18期268-276,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点研发计划项目
猪舒适环境的适宜参数与限值研究
项目编号:2016YED0500506
关键词
温度
湿度
通风
射流
湿帘冷风机-纤维风管
猪舍
temperature
humidity
ventilation
jets
wet curtain fan-fabric duct
sow barn
