Multiple factors of early embryonic losses in dairy cows

The aim of the research was to study the factors of early embryo mortality (EEM) expansion and the ways of its minimization to determine the possibilities of maintaining cows’ productivity. About 4 thousand Ayrshire cows were studied. The influence of para-typical, physiological and hereditary factors on EEM was taken into account. An indirect method, based on the recording of durations between intervals of contiguous cow inseminations was used to register EEM. EEM was registered in 21,7 % cows with a high variation factor (39,5 %). The low level of EEM was observed in the cows with the first lactation (12,1 %), the highest level (27,3 %) was registered in old cows (seven lactations and more). The lowest level of EEM was registered in cows after the first insemination in 2,5-3,5 months after the first calving (10,8-7,4 %); the highest one - in 4 months and later (44,4 %; P