Characterisation and pattern of culling in Holstein-Friesian dairy herds in Khorasan Razavi Province, Northeast of Iran

To describe proportion and pattern of culling in commercial dairy herds of Khorasan Razavi Province, this survey was carried out from ۲۱st March ۲۰۰۸ to ۲۰th March ۲۰۰۹ in ۱۵ industrialized dairy herds. For each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. Annual herd exit rate was ۲۰.۹%. Out of a total of ۶۵۲ culled cows, the proportions of culled dairy cows were due mainly to involuntary culling with very small proportion of voluntary culling (۴%). The involuntary culling were mainly from infertility or reproductive disorders (۲۳.۶%), udder disorders (۱۷.۵%) and digestive tract disorders (۱۵.۹%). Average ± SD of parity at culling was ۳.۱۵ ± ۱.۹۶. Culled cows from digestive tract disorders, injuries and infectious diseases were significantly younger than those of other culling reasons (P < ۰.۰۵). Mean ± SD of last calving to culling interval was ۱۹۴ ± ۱۵۹ days. Culled cows from digestive tract disorders, injuries and udder disorders were removed earlier in lactation period than cows culled from reproductive disorders, infectious diseases and lameness (P < ۰.۰۵). Low proportion of voluntary and high percentage of involuntary culling specially from health problems should be considered as an important economic loss and precaution measures are necessary to reduce this loss.

کلیدواژه ها:

Culling ، Voluntary ، Involuntary ، Holstein dairy herds ، Iran