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:高腾云[1] 李敬波 李守义[1] 姚卫民 杨雪峰[1]
机构地区:[1]河南农业大学,郑州450002 [2]洛阳奶业公司,洛阳471013 [3]东方正大饲料公司,洛阳471013
出 处:《家畜生态》2001年第4期39-42,共4页Ecology of Domestic Animal
摘 要:1991~ 1 994年在洛阳市奶牛场连续观察散养与栓系饲养体制下奶牛的发情表现、发情地点及每日的发情时间分布 ,统计每月的受胎率和奶牛的产后首次配种时间。结果表明 :在散放饲养条件下 ,奶牛发情明显 ,发情行为期长 ;夏、冬季的受胎率低于春、秋季 ,明显地受温度的影响和五项气象因素的综合作用 ;五项气象因素对产后首次配种时间的综合影响显著。The heat performance, heat Location and heat time in each day in the free stall barn system and the tethering system were observed on the Luoyang dairy cow farm from 1991 to 1994, and the pregnancy rate and the time of postpartum heat were calculated. The results showed that in the free stall barn system the estrous signs of dairy cows were more obvious and the estrous duration was longer than that in the tethering system; the pregnancy rates in summer and winter were lower than that in spring and autumm, which were apparently affected by the temperature and by all of the five meteorological factors comprehensively; the five meteorological factors affected the postpartum heat significantly.\;
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:18.119.131.79