Abstract
The paper highlights the results of the analysis of the main reasons for the culling of cows and established their relationship with age. The studies of animals of different lines confirm that with an increase in the period of economic use, the productive life of cows, as well as their lifelong milk production, is also extended. The duration of the economic use of cows has a certain dependence on their productive characteristics, namely, more productive animals deplete the resources of their bodies more quickly and, as a result, are more likely to be rejected. On the other hand, animals with a steady, albeit somewhat smaller display of milk productivity during life longer retain the ability for productive use and this is more profitable from an economic point of view.
Keywords:
retirement of cows, reasons for culling, productive longevity, duration of economic use, lifetime performance, coefficient of utilization of cows.