EN
The aim of the study was to compare reproduction parameters of Montbeliarde (MO) and Polish Holstein Friesian Black and White (PHF) cows kept in farms representing different production systems and scale. Researches were conducted on cows in six farms located in the south of Poland keeping both MO and PHF breeds. Data on 2782 cows (980 MO and 1802 PHF) were collected. Analyzed were the following reproduction parameters: gestation length, insemination index, interval between firs and fertile insemination, average insemination interval, open days, calving interval. The analysis of heifer reproduction parameters confirmed that PHF heifer fertility was better than that of MO heifers; however, differences were not significant. Moreover, PHF heifers reached reproduction maturity earlier than Montbeliards (P ≤ 0.01). The analysis of cow fertility also confirmed the influence of breed on reproduction indicators. Montbeliarde cows had a significantly longer mean inter-insemination period than PHF cows as well as a longer inter-calving period. PHF cows were characterized by a lower insemination index than MO. Lower values of reproduction parameters, especially those closely connected with herd management, indicate that Montbeliarde breeders should devote more attention and time to estrus detection in their herds.