Martin S W, Schwabe C W, Franti C E
Am J Vet Res. 1975 Aug;36(08):1111-4.
Data on calf mortality, calving site, calf-rearing facilities, and calf-management procedures were collected from 16 dairy farms in Tulare County, California. Discriminant analyses were used to test if any significant differences in these factors existed between farms with higher than average and farms with lower than average death losses. The average mortality rate over a period of at least 2 years on individual farms varied from a low of 3.5 +/- 1.1% to a high of 30.6 +/- 3.1%. Calf management personnel was the only factor significantly related to the mortality rate, with considerably fewer death losses on farms where the owner managed the calves than on farms where employees performed these duties. In general, other factor categories relating to size of the cow herd, calving site, and calf housing were not related significantly to calf deaths. The average number of heifer calves born each year on individual farms was increasing year by year, and on some farms, there seemed to be a concomitant increase in death losses. This, together with the tendency toward greater number of deaths on the larger owner-managed farms, indicated that calf care was diluted under these conditions.
从加利福尼亚州图莱里县的16个奶牛场收集了有关犊牛死亡率、产犊地点、犊牛饲养设施和犊牛管理程序的数据。使用判别分析来检验在高于平均死亡损失的农场和低于平均死亡损失的农场之间，这些因素是否存在任何显著差异。各个农场至少两年期间的平均死亡率从低至3.5±1.1%到高至30.6±3.1%不等。犊牛管理人员是与死亡率显著相关的唯一因素，在由农场主管理犊牛的农场，死亡损失比由员工履行这些职责的农场少得多。一般来说，与牛群规模、产犊地点和犊牛饲养有关的其他因素类别与犊牛死亡没有显著关系。各个农场每年出生的小母牛犊数量逐年增加，在一些农场，死亡损失似乎也随之增加。这一点，再加上较大的由农场主管理的农场死亡数量增多的趋势，表明在这些情况下犊牛护理工作被淡化了。
