Stankov V G
Vet Med Nauki. 1978;15(1):34-42.
Stated are the drop in milk productivity and the total losses in a value expression as determined by a definite formula. The observations were carried out on four large dairy farms. The cows on each farm were divided into groups according to the number of lactation and the length of the intercalving period. It was found that in 84 per cent of the cases of cows with a prolonged intercalving period the average daily milk yield for the same period was lower than in the case of cows with a normal duration of this period. Calculated were also the K coefficients, showing the milk loss, per lost service-period day. With a small group of cows there was an increase in the milk yield per each lost service-period day. The K coefficients were shown to vary with the individual groups of animals. At the same time most of the calculated values, indicating the loss of milk in sterility, were statistically insignificant. This was due to the expressed individual character of the response of sterile cows with regard to the drop in milk productivity. It was rather difficult to refer to a certain definite and general normativ as attempted by some authors. The guiding principle in the culling of sterile cows should be based on the individual approach. The data are given in two tablets.
文中阐述了牛奶产量的下降情况以及根据特定公式确定的价值表达中的总损失。观察是在四个大型奶牛场进行的。每个农场的奶牛根据产犊次数和产犊间隔期的长短进行分组。结果发现，在84%的产犊间隔期延长的奶牛案例中，同一时期的日均产奶量低于产犊间隔期正常的奶牛。还计算了K系数，该系数显示了每损失一个配种期日的牛奶损失量。在一小群奶牛中，每损失一个配种期日的产奶量有所增加。结果表明，K系数因动物个体群体而异。与此同时，大多数表明不育导致牛奶损失的计算值在统计学上并不显著。这是由于不育奶牛对牛奶产量下降的反应具有明显的个体特征。很难像一些作者所尝试的那样参考某个确定的通用标准。淘汰不育奶牛的指导原则应以个体方法为基础。数据列于两个表格中。
