Indicii de reproducție și interrelațiile cu productivitatea de lapte la populațiile de vaci din diferite rase specializate pentru lapte

Abstract

The reproductive characteristics of cows of different breeds (Holstein, Jersey, Moldavian type of the Black-Motley breed) specialized for milk, exploited in conditions 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 exceeded the optimal term (365 days) and changed concomitantly with the change in the service 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.