Study of productive and reproductive parameters in cows from Holstein-Friesian breed

Georgi Popov, Zapryanka Shindarska, Iliya Ralchev

Abstract: A study was conducted with cows of Holstein-Friesian breed. It includes 152 number of animals
separated and aligned into groups according to sequence and number of lactations. We trace the
following reproductive parameters: age of mating, calving age, length of service and independents
period, number of insemination, duration of pregnancy and calving period. Parallel to this are investigated some productive parameters, such as milk quantity of lactation, duration of lactation and dry period. The aim of the study is to establish some reproductive and productive performance of dairy cows with different lactation placed under the same technological conditions, feeding and breeding. It was found extending lactation than optimal (305 days), increasing the number of insemination for breeding, increase the age of calving and extending the service and calving periods.

Keywords: cows; lactation; production; reproduction; service period; sexual cycle

Date published: 2017-02-09