HOLSTEIN BREEDS DEPENDING ON THE ESTIMATION OF THE UDDER-MASS-METRIC INDEX

Abstract

The study on the evaluation of cows first-born of Holstein and Ukrainian Black-and-White dairy breeds by udder-mass-metric index (UMMI) was conducted in the herd of the company "Ukrlandfarming" PE "Burynske" Pidlisnivsky branch of Sumy region. The distribution of groups evaluated by the udder-mass-metric index of cows first-born of experimental breeds, depending on the value of index within the gradations of three conventional units into five classes, revealed a clear pattern of the correlative influence of its level on cows milk productivity. With each subsequent increase in the value of UMMI by three conventional units, the average yield of cows of each group gradually increased in both cows of Holstein and Ukrainian Black-and-White dairy breed. The difference be-tween adjacent classes in Holstein cows first-born ranged from 222 kg (between classes 7.1-9.0 and 9.1-12.0 conv. units) to 503 kg (between classes 15.1-18.0 and 18.1 or more conv. units. Between the extreme classes, the difference in the milk yield for 305 days of the first lactation was significant and amounted to 1283 kg (P <0,001). In the cows first-born of Ukrainian Black-and-White dairy breed, the significant difference between adjacent classes by milk yield ranged from 127 kg (between classes 9.1-12.0 and 12.1-15.0 conv. units) to 568 kg (between classes 15.1-18.0 and 18.1 or more conv. units; P <0.001). In animals of the Holstein breed UMMI averaged 15.0, and in the Ukrainian Black-and-White dairy - 13.1 conv. units with an intrabreed difference of 1.9 conv. units with a reliability of P <0.001 in favor of Holstein cows. The established reliable correlative relationship between the udder-mass-metric in-dex and indicators of milk productivity testified about the possibility of its effective use in mass selection of cows according to the conformation type.