BODY WEIGHT OF DIFFERENT GENEALOGICAL LINES OF THE GRAY UKRAINIAN BREED OF HEIFERS AS A FACTOR OF DETERMINING ITS CONSOLIDATION AND CROSSING EFFICIENCY

Abstract

In the dynamics of 2002-2019, a slight increase in the number of cattle of the Ukrainian Gray breed has been determined against the background of a slight increase in milk yield of cows with the first calving and yield of calves per 100 cows, as well as decrease in the growth rate of young animals. The purebred livestock of the Ukrainian Gray breed belongs to two genealogical lines: Shamrin XY-141 and Petushok 191-Y and is kept only in two breeding herds of Ukraine. A comparative assessment of body weight of heifers at the age of 210 days and 8 months indicates the advantage of young stock of Shamrin XY-141 line over the Petushok 191-Y line by 4.7 kg and 1.6 kg, respectively. Further, the advantage was on the side of the representatives of Petushok 191-Y line, but with no statistically significant difference between them. The body weight variation ratio of heifers of Petushok 191-Y line during rearing made 6.06-13.81%, and Shamrin XY-41 - 7.11-13.88%, indicating insignificant, but still possibility of increasing the trait by breeding method. Crossbreed heifers were inferior to purebred in terms of body weight and weight gain during rearing, indicating inappropriateness of interbreed selection of animals of the local population with modern breeds of beef cattle.