Reproductive Longevity of the Russian Black Pied Cattle Depending on Period Length between Calving

Abstract

The article deals with the indicators of reproductive longevity of the Russian black pied cattle depending on the period length between calving. The research object is the data of the electronic database of OAO “Zarya” of the Vologda Oblast. We divided animals of the study sample into four groups depending on the duration of the calving interval. We have studied indicators of productive longevity and reproductive qualities of cows. We have calculated underproduction with an increase in the duration of the calving interval. The highest number of completed lactations (3.4) and a fairly high lifetime milk yield of 25.6 kg are established in group II (calving interval is 366–425 days). This animal group has the highest milk productivity per day of life (10.5 kg), as well as a higher number of live calves (4.26 heads). Lower indicators of lifetime productivity, calf yield and reproductive qualities are obtained in group I (up to 365 days).