The reproductive characteristics of cows of different breeds (Holstein, Jersey, Moldavian type of the Black-Motley breed) specialized for milk, exploited in condi-tions of the Republic of Moldova, were studied. Compared to the maximum allowed value of the service period (90 days), the difference is +48.0 days for Holstein cows, +38.9 days for Moldavian type Black-Motley and for Jersey cows +104.9 days. Value of the service period according to the race hates statistically genuine differences lower by 76.0 days (P<0.001) in the outochtonous type and by 56.9 days in the Holstein breed, compared to the Jercey cows population. Duration of the calving interval in the analyzed groups ex-ceeded the optimal term (365 days) and changed concomitantly with the change in the ser-vice period. The birth rate depends on the length of the service period, the best result is found in the population of Moldovan type of the Black-Motley breed. Between service period and indices of milk productivity, correlative links were found, in a predominantly positive direction, in magnitude from very weak to strong, depending on the breed, but also on the studied index.