REPRODUCTIVE ABILITY OF HEIFERS AND COWS FIRSTBORN OF UKRAINIAN BLACK SPOTTED DAIRY BREED WITH DIFFERENT ORIGIN
There was analysis of the reproductive ability of cows firstborn Ukrainian black and white dairy cattle that were daughters of 20 Holstein bulls-sires. It was established that their parents had considerable influence on the reproductive capacity indicators of their daughters. Age of first insemination and first calving and duration of service- and intercalve periods coefficient reproductive capacity and output of calves per 100 cows in different sires daughters were accordingly within 16,3-22,0 and 25,5-31,3 month, 107,7-245,8 and 390,8-526,1 day and 0,73-0,97 73,2-97,0 heads. The highest losses of milk per lactation days due to infertility had daughters of bulls Selvihara 14911, D.Kaprisa 401393, P.I.Serzhanta 388785 and Dzhupitera 14464 and lowest - daughter bulls cots Manege 685, Malishа 683, Etalonа 719, M.Bruna 5488517 and V.P.V.Starbaka 389756. The largest share of the impact of parents was on the age of the first insemination and calving heifers duration of pregnancy and during lactation milk loss due to days of infertility, which respectively accounted for 13,88; 13,91; 11,35 and 11,39 % at P<0,001 in all cases. Lower impact bulls had the following performance index insemination of cows firstborn, adaptation index and fertility index.