The increased air temperature combined with the reduction of rainfall during hot season impairs the capacity of cows to maintain the optimal body temperature. This study tested the hypothesis that climate changes affect the medium yielding cows in temperate continental climate. The productive-reproductive parameters of 8607 milking cows from a dairy farm in North-eastern Romania were examined and correlated with changes in ambient temperatures and rainfall between the years of 1983 and 2010.
We observed that the number of artificial inseminations served to cows showed a decreasing trend. The reduction in this parameter was significantly influenced by the increase in the average and maximum temperatures during hot season associated with the reduction in rainfall, as shown by regression analysis. Other studied parameters such
as milk production, calving to conception interval, calving to first artificial insemination interval and conception rates at first, second and more than two services were not related to the changes in average annual temperatures, annual temperatures amplitude and annual precipitation quantities. This study suggests that, although present, the effects of climate changes on some productive-reproductive parameters of medium yielding cows in geographic areas with temperate continental climate are not as dramatic as described in other studies.