Aim: In this study, it was aimed to determine the reproduction traits together with environmental effects on different Holstein breed reared in a private intensive dairy in Kırşehir.

Materials and Methods: The material used in the study was comprised of the data between 2011-2014 of the pregnant Holstein heifers and their calves imported from the USA and Estonia in 2011-2012. In the study, records of 260 cows (118 from USA, 142 from Estonia) for reproductive performance, records of 79 cows from Estonia for first AI dates was analyzed.

Results: At the result of this study the proportional reproductive parameters found as; pregnancy, calving, stillbirth and abortion rates were 95.8 %, 88%, 3.3% and 8.7 %for all cows; 94.3%, 85%, 4% and 10.1% for Estonian Holsteins; 98.5 %, 93.1 %, 2 %, and 4.9% for USA Holsteins respectively. Age at first insemination, interval from first insemination to pregnancy, number of insemination per pregnancy and first calving age of reproductive performance traits were 445.97±3.75 d, 13.04±2.96 d, 1.354±0.076 and 24.590±160 d for Estonian Hosteins.

With regard to reproductive performance parameters; Origin of cows and calving season was significant (P<0.05 and P<0.001) on days to first service and first to last insemination interval (P<0.01 and P<0.05). Origin of Holsteins and calving year was also significant (P<0.001 and P<0.05) on days open and number of insemination per pregnancy(P<0.05 and P<0.05). Origin of Holsteins and calving age had effect on calving interval (P<0.05 and P<0.05). No significant difference was found for gestation length.

Conclusions: It can be concluded from this study that USA Holsteins are preferable to Estonian Holsteins in Kırsehir region of Turkey.