the change in the number of animals of various production and age groups for a calendar period. The herd turnover for a report period shows the actual changes in the herd. The turnover projected by the plan, or the planned herd turnover, is the basis for calculating the commodity output and its gross value for stock raising and the increase in the number of head, as well as for determining the demand for feed, production facilities, and manpower. The herd turnover is calculated for major farming enterprises or for specialized stock-raising farms, brigades, and departments. Herd turnover is related to the reproduction of the herd and the herd composition.