EXTERIOR CHARACTERISTICS OF HOLSTEIN CATTLE OF DIFFERENT ORIGIN AND THE RELATIONSHIP OF COMPLEX TRAITS TO MILK PRODUCTIVITY

A linear assessment of first-calf heifers was conducted based on exterior type at the "Ostriykivske" dairy-industrial complex in Kyiv region (n = 180 heads). The degree of development of the main descriptive exterior traits of first-calf heifers of Holstein breed indicates significant intrastadial variability. Cows of different paternal origins differ in the development of certain body parts. The influence of sire on the variability (12.95‒37.69%) of the descriptive traits of linear classification by type was revealed. The highest rating for the complex of traits (86.72 points) and the best milk productivity (yield – 12.942 kg, fat – 546 kg, and protein – 427 kg) is observed in the daughters of the bull Elkhart US3148929453of Holstein breed. The offspring of the bull Password CA13638215 have the lowest rating for the complex of traits (80.11 points) and a lower yield – 8.554 kg compared to the daughters of other bulls. A strong, statistically significant correlation was established between the overall type score and the amount of milk yield (r = 0.740) in first-calf heifers of the Holstein breed. A high level of significant positive correlation was found between the group traits of the exterior and the milk yield during the first 305 days of lactation, which characterize the expression of the milk type (r = 0.323), body development (r = 0.438), udder (r = 0.545), and limbs (r = 0.332). The correlation coefficients between the descriptive traits of type and the milk yield of Holstein first-calf heifers over 305 days of lactation showed significant variability, ranging from negative (r = -0.168) for the angle of the pelvic limbs (side view) to moderate positive (r = 0.493) for the front attachment of the udder.