Heat stress alleviation for dairy cows housed in an open-sided barn by cooling fan and perforated air ducting(PAD)system  

作　　者：Xie Lina Wang Chaoyuan Ding Luyu Gui Zhiyuan Zhang Lu Shi Zhengxiang Li Baoming Jia Chuntao 

机构地区：[1]Department of Agricultural Structure and Bioenvironmental Engineering,College of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China [2]Key Laboratory of Agricultural Engineering in Structure and Environment,Ministry of Agriculture,China Agricultural University,Beijing 100083,China [3]Engineering Research Center on Animal Healthy Environment,Beijing 100083,China [4]Hailin Dairy Farm,Shigezhuang Town,Tianjin 301718,China

出　　处：《International Journal of Agricultural and Biological Engineering》2017年第6期1-10,共10页国际农业与生物工程学报（英文）

基　　金：This study was funded by National High Technology Research and Development Program(2013AA10230602);China Agricultural Research System(CARS-36).A special thank for all the help from Hailin Dairy Farm,Tianjin,China,where the field evaluation was conducted.

摘　　要：Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in China.Many farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ventilated shed,which can result in decreasing feed intake and milk production.For alleviating heat stress and improving animal comfort,a system consisting of an air cooler and a 30 m perforated air duct(PAD)was integrated to evenly distribute cooling air.The air was cooled by underground water and delivered to targeted zones above stall bed.The system was evaluated in an open sided dairy barn in Tianjin,China.For the stalls equipped with PAD system,air velocity reached above 1.1 m/s at 0.5 m height plane of the stall space,and was more uniformly distributed.Compared to the stalls equipped with circulation fans,the PAD system lowered air temperature by 1.5℃,and increased relative humidity by 8.1%.On average,Temperature Humidity Index(THI)and Equivalent Temperature Index(ETI)were decreased by 0.5 and 0.6,respectively.After a 15 days’operation of the system,rectal temperatures of the treated dairy cows were significantly lowered.The results also showed that the cows under PADs had a higher milk production.These findings suggest the PAD can be an effective cooling alternative for naturally ventilated dairy barns to alleviate heat stress.

关 键 词：dairy cow heat stress perforated air duct cooling fan naturally-ventilated barn 

分 类 号：S82[农业科学—畜牧学]