ESTIMATION OF COWS EXTERIOR IN INCREASING THEIR PRODUCTIVE LONGEVITY

Abstract

The paper analyzes indexes of productive longevity of black-and-white cows of different exterior. The author speak about the complex estimation of first-calf cows exterior, which allows forecasting the indexes of their productive longevity. The cattle studied had average indexes of pelvic position, hind feet position, heel angle and altitude of rear udder. The cows are characterized by small body depth, contracted pelvis, long rump and wide position of fore teats; they had high position of udder, strong fore udder attachment, above average stature, big muscles, breast and tough body. The first-calf heifers of “Khoroshiy” complex class surpassed the cows of other groups in lifetime and time of economic efficiency on 2.6 year and 2.1. year of lactation, life milk yield on 10 525.4 kg and milk fat on 263.2 kg. The cows of this group didn’t have any abortions or deformities after calving; all the calves were born alive. The authors formulate the idea, that periods of breeding and commercial applying relate to animals lifetime; when cows lifetime increases their economic applying increases as well (r = +0,94, R = 0,91). The authors point out high correlation between the lifetime and life milk yield (r = +0,92, R = 3660,8) and milk fat (r = от +0,69, R = 89,4; whereas the factor of constitutional type affects the animals’ longevity almost the same way (в среднем 11,4 %).