The influence of some factors (season and age of the first caving, paternal origin, duration of economic use) on milk productivity of cows on farms in the Middle Amur Region

The results of analysis of the primary zootechnical registration in two dairy farms of the Khabarovsk region are presented. The biological reserves of raising the economic efficiency of milk production by means of elimination of incorrect distribution of calvings by year seasons, lowering of the first calving age to 27 months and the cow productivity period raising to 5 and more calvings for Black-and-White breed are determined.