EXTERIOR FEATURES OF COWS FIRSTBORN OF SUMY INTRABREED TYPE OF UKRAINIAN BLACK-AND-WHITE DAIRY CATTLE, ESTIMATED BY THE METHOD OF LINEAR CLASSIFICATION

Abstract

To study the traits of exterior type of firstborn cows of Sumy intrabreed type of Ukrainian Black-and-White milk breed, a research was carried out in the breeding flock in Sumy region. The first-calf cows were estimated by the method of linear classification according to the age of 2–4 months after calving in two systems – 9-score, with a linear description of 18 conformation traits, and a 100-point classification system, taking into account four sets of breeding traits that characterize: dairy type, body development, condition of legs and feet, and udder morphological qualities. Results of linear estimation cows firstborn in the experimental herd on a 100-point scale indicated that traits within the group average final score was in the range of "good plus." Cows-firstborn were characterized by good development of group traits defining their dairy type (82.9 score), body trait development (84.1 score), condition of legs and feet (82.3 score), udder (82.6 score) and final type score (82.9 score). The development level of 18 conformation traits of cows showed their significant variability inside a controlled herd. In general, estimated animals in the breeding flock of PE "Burynske" of Pidlisnivskoy branch were characterized by well-defined height, body depth, angularity, rump angle, rump width, fore udder attachment, central ligament and udder depth. The results of linear classification showed that body structure of the first-born cows of Sumy intrabreed type of Ukrainian Black-and-White dairy breed at the present stage of selection had a rather good characteristic of descriptive traits that determined their dairy type. According to results of research, first-born cows with estimation "very good" exceeded peers with score "good plus" by milk yield with highly reliable difference of 583 kg (P < 0.001), and with score "good" – at 1884 kg, the difference was also highly reliable at Р ˂ 0,001 With unreliable reducing the fat content in milk from cows with score "good plus" and "good", milk fat gain at firstborn with the assessment "very good" was compared in animals with score "good plus" 20.8, and "good" – at 68.8 kg (R ˂ 0,001). Use in dairy cattle selection process of linear classification method was very effective objective definition of pedigree cows exterior features and a link between the group of linear traits and milk yield – guarantee the efficiency of selection of animals by type.