INFLUENCE OF ORIGIN ON MILK PRODUCTIVITY AND REPRODUCTIVE PROPERTIES OF SYCHEVSKAYA BREED COWS

Abstract

The results of researches on studying of sires influence on milk production and reproductive properties of Sychevskaya breed cows, bred in the breeding farm, JSC "Vostok", Smolensk region. In order to determine sires, cows, which are able to increase milk productivity of the herd without compromising reproductive properties, population of full-aged cows, according to their origin, was divided into six groups. Their milk yield was analyzed for first and third lactations, mass fraction of milk fat and milk protein, live weight, coefficients of milk yield of cows and the sustainability of lactation. The most stable, in all groups, is the first lactation, then there is a decrease to the fifth lactation. Cows received from the bull of Sychevskaya breed Pyl 6782, for the first lactation have a productive advantage over livestock received from other bulls. In full-aged animals derived from this bull, this advantage is lost. The daughters Hanke 6749, Holstein red-and-motley breed, have intensively promoting milk productivity, indicators of milk fat and protein is higher in daughters of Holstein bull Marder 6721. Reproductive properties were studied: open days and calving interval, age at first calving, days to first fertilization in lactation. The best reproductive properties have Sychev bulls. After calving, reproductive function in daughters Naliv 6791(sychevskaya breed) were restored earlier, in daughters Hanke 6749 - for longer period. The correlation of signs is defined: milk yield between lactations, milk productivity with mass fraction offat%, live weight, age of the first calving, the period of days before the first insemination in lactation.