STUDY ON MILK PRODUCTIVITY AND PRODUCTIVE LIFE SPAN OF COWS FROM BULGARIAN SIMENTAL BREED

Petar Stoikov, Verginia Gaidarska, Tatiana Ivanova, Tsvetana Harizanova

Abstract: The aim of this study was to determinate milk productivity, productive life span, and longevity of Bulgarian simental cows with different lactation. The data of milk production and duration of lifetime productivity for 312 cows, daughters of 14 bulls from Bulgarian simental breed, was used, during 1980 – 2001 period. For establishment the efficiency of productive and reproductive indices of cows a study have been used The objectives of the study were milk productivity, maximum milk yield, age of first lactation, productive life span, farming using, days, longevity, productivity using of cows, lifelong milk yield, milk yield for 1 lifelong day, lifelong number of lactation, lifelong number of calves. The results obtained showed that cows of simental breeds has had milk productivity from 2 911kg to 3 450 kg milk yield, productive live span of cows is 1 601.6 days, and lifelong milk yield is 12 864 kg, with 4.09%
fatty substance (F.S.).The longevity of cows from simental breed is over 5 lactation, lifelong number of lactation is approximately 4.23 while lifelong number of calves is 4.57.

Keywords: age of calves; bulls; cows; lactation; longevity; milk productivity; productive life span

Date published: 2023-01-25