DYNAMICS OF GROWTH OF LIVING WEIGHT OF UKRAINIAN RED-BROWN DAIRY BREED HEIFERS OF DIFFERENT LINES

Abstract

The article presents the results of research on the dynamics of live weight growth, absolute, average daily and relative growth of heifers of the Ukrainian red-spotted dairy breed, obtained from breeders of different lines. The aim of the research was to establish the influence of linear affiliation on the growth dynamics of live weight of heifers. For this purpose, a database of 288 heifers was developed, which belongs to six lines: Chief, Elevation, Cavalier RF, Cadillac RF, Marshall and Starbuck. Live weight and gains were studied from birth to 15 months of age with an interval of 3 months according to generally accepted methods. Feeding and housing conditions for animals of all groups were the same. As a result of the conducted researches it is proved that live weight and gains of heifers depend on linear affiliation and age period. The average daily gain of heifers from birth to 3 months of age was in the range of 782.2-871.9 g, and was the highest compared to other age periods, except for heifers of the Cavalier RF. With age, the average daily gain decreased and reached its minimum in the last study period of 12-15 months - 598.6-687.9 g. For the entire study period from birth to 15 months of age, the average daily gain of heifers of all lines was 833.1-898, 0 g. In terms of linear affiliation, the best growth dynamics and increments were characterized by heifers originating from the breeders of the Marshall line. At 15 months of age, Marshall heifers weighed 387.4 kg, which is 7.8-26.3 kg more than their peers. Studies have shown that under the same conditions of feeding and keeping heifers obtained from the broods of the Marshall line grow faster and earlier reach the required live weight for the first insemination.