James R E, McGilliard M L, Hartman D A
J Dairy Sci. 1984 Apr;67(4):908-11. doi: 10.3168/jds.S0022-0302(84)81387-9.
Information concerning heifer calf mortality and dairy herd management practices was obtained by survey of 407 Virginia Dairy Herd Improvement herds. Dairy producers, with the assistance of Dairy Herd Improvement supervisors, accounted for mortality of all heifer calves born from October 1, 1978 to March 31, 1979. Calf mortality was compared among herd sizes, fat and milk production, cow and calf housing systems, calving locations, and calf feeding practices. Average herd size was 82 cows with 87% of herds containing fewer than 120 cows. Mortality at birth and from birth through 3 mo of age averaged 1.2 and 6.5%. Mortality at birth was correlated .10 with herd size. Losses from birth through 3 mo of age were correlated .10 with age at weaning and -.16 with rolling yearly average milk and fat production. Relationship of mortality with other herd characteristics or management practices was negligible.
通过对407个弗吉尼亚奶牛群改良牧场进行调查，获取了有关小母牛犊死亡率和奶牛群管理做法的信息。在奶牛群改良监督员的协助下，奶农统计了1978年10月1日至1979年3月31日出生的所有小母牛犊的死亡情况。对不同畜群规模、脂肪和牛奶产量、母牛和牛犊饲养系统、产犊地点以及牛犊喂养方式下的犊牛死亡率进行了比较。平均畜群规模为82头奶牛，87%的畜群奶牛数量少于120头。出生时和出生至3月龄时的死亡率平均分别为1.2%和6.5%。出生时的死亡率与畜群规模的相关性为0.10。出生至3月龄时的损失与断奶时的年龄相关性为0.10，与年度平均牛奶和脂肪产量的相关性为-0.16。死亡率与其他畜群特征或管理做法之间的关系可忽略不计。
