D. Cozma

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CONTRIBUTIONS REGARDING STUDIES ON MILK PRODUCTION AND REPRODUCTIVE CHARACTERISTICS OF THE BNR POPULATION IN DOAGA-VRANCEA FARM

D. Cozma, V. Ujică, I. Nistor, C. Dascălu, C.E. Nistor

Abstract
The Romanian Black spotted held in one of the best elite farms in the country, placed in Vrancea County, was studied over 15 years (approximate three generations).
The cows of active population and those out of herd were studied as concern: the descendency depending on the provenance of sires (indigenous or imported); the characteristics of milk production, for normal and total lactation and subsequent lactation; the reproduction characteristics: VPF, CI, RM, SP; the productive longevity.
The results indicate that cows descending from imported sires have a mean production of 7496.44 kg milk per normal lactation and those descending from indigenous sires produced a mean of 7367.79 kg milk, that means a genetic gain of 128 kg milk (1.74%).
The active population of the investigated holding attained 7,426 kg milk compared to the out of herd population with a mean 7,291 kg milk per normal lactation. A genetic amelioration of 135 kg milk (1.85% genetic gain) from a generation to another was observed.
The age at first calving was 835.97 days; the calving interval was 439.48 days and the dry period 80.6 days.
The mean holding period was 2.77 lactations and the milk quantity per productive life was 23328.9 kg.

Key words: BNR breed, productive and reproductive performances, longevity