EN
The research involved 432 cows, with an average yield of about 10 000 kg of milk in 305-day lactation, kept on a dairy cattle farm in south-western Poland. The aim of the work was a comparison of reproductive and economical features (EJR - index economischjaarresultaat - from Dutch) of Polish Holstein-Friesian breed cows of Black- and Red-White variety with a different contribution of genes of Holstein-Friesian (HF) breed cattle, after the first five calvings. The genotype of cows had a statistically significant influence (p ≤ 0.05, p ≤ 0.01) on the value of sexual rest, inter-pregnancy and inter-calving periods, and also the economical value expressed as the EJR index. It also significantly differentiated the magnitude of the fecundation index and sexual rest period, and economic value of the analyzed groups of cows. In cow herds, especially of Black-White breeds with a high contribution (> 87.5%) of HF cattle genes, the elongated sexual rest, inter-pregnancy and inter-calving periods, poorer survivability until subsequent calvings, and higher economical value (in euro) than in the case of their Red-White age mates should be expected. In heifer cows of high milk yield, lower reproductive feature indices (inter-pregnancy and inter-calving periods, fecundation index) and poorer economical value (EJR index) than in multiparous cows should be expected.