【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。更多还原

【Abstract】 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.\;更多还原