检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:Xiong Haozhe Chen Zhaohui Xu Yiming Yang Hao Liu Jijun
出 处:《Animal Husbandry and Feed Science》2019年第5期140-144,共5页动物与饲料科学(英文版)
摘 要:[Objective]The paper was to study the wind-reducing effect of windbreak wall at different sheltering distances and the effects of wind speed on cattle performance.[Method]The 40 cattle with insignificant difference in initial weight were randomly distributed in four selected stalls,and were divided into two groups according to the distance between stalls and windbreak wall to measure their daily gain.According to the actual conditions and weather conditions of fattening cattle farm,the wind speed,temperature and other environmental indexes of measuring point and heat production of beef cattle were carried out field measurement and analysis.[Result]The windbreak wall in fattening cattle farm reduced the wind speed by 40%-70%within a horizontal distance of 10 times of the wall height at a height of 1.2 m.The best sheltered area behind windbreak wall was 2-4 times of the height of windbreak wall.Within the distance of 6 times of the wall height,the wind speed reduction effect was obvious and the maximum reduction rate reached 70%.With an external WCI of-15.61 and average beef cattle weight of 480 kg,the WCI of fattening cattle farm equipped with windbreak wall reached-9.00,and the heat loss reduced by each cow was 3.31 MJ/h.Meantime,due to the difference in distance from windbreak wall,the daily gain difference of beef cattle was 0.15 kg/head day,but the difference was not significant(P>0.05).
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.51