Effects of environmental factors on reproductive performances of holstein cows and heifers

Abstract

During the research period (1997 - 2000) based on 1475 records in Holstein cattle, pregnancy, normal calving, abortion and still birth rates were estimated as 88.9%, 93.1%, 1.9% and 1.0% respectively. For Holstein heifers, the age for first insemination, number of insemination per conception and age at first calving were 494.1 days, 1.25 and 784.7 days, respectively.