Selection and breeding work plays a significant role in improving dairy cattle. Today in Ukraine on the basis of the gene pool of the best performance in terms of world species, primarily Holstein, a number of new domestic breeds of dairy cattle have been created. Further genetic improvement of new breeds requires modernization of all elements of selection and breeding, including evaluation system of genetic value.

Historically, the first method of sires assessing was the method of comparison daughters with mothers (Daughter-Dam Comparison), which was used from the 1920s. In the early 1960s it was replaced by comparison – (Herd mate Comparison), and then (early 1970s) – modified by comparison with peers (Modified Contemporary Comparison, MCC). In the first half of 1970, thanks to the work Ch. R. Henderson method of best linear unbiased prediction was developed (Best Linear Unbiased Prediction, BLUP), and later it was used for breeding value estimation of all major types of farm animals, first as a «sire model» (Sire Model), and later – more powerful «animal model» (Animal Model).

It should be noted that today dairy farming of some countries almost made the transition from traditional evaluation system of bull-sires by offspring to the system  of genomic selection, in which young bulls are selected for breeding at an early age based on genomic evaluation of breeding value (Genomic Breeding Value, GBV). However, the method BLUP is also used in practice and in this system, but in a modified form as genomic BLUP.

The purpose of research – evaluation of breeding value of sires and cows of dairy breeds. To achieve the goal the following tasks were set: develop a model for evaluating bulls-sires of dairy and dual direction of productivity; to evaluate breeding and genetic parameters of selecting and breeding; determine the correlation between genetic characteristics of cows of different breeds.

As a result of conducted investigation we obtained data of the values of milk production – milk yield during 305 days of lactation, the amount of milk fat and protein during 305 days of lactation, reproduction data - period between calving and productive longevity of cows of four breeds.

Holstein breed cow are characterized by the greatest level of milk production of cows. Animals presented breeds differ in terms of milk yield – 5490: 4544: 4520: 4344 (p<0.001). Holstein breed prevails Ukrainian Red-and-White dairy breed – 5490 kg to 4520 kg (p<0.001). Cows of Ukrainian Black-and-White dairy breeds and Ukrainian Red-spotted dairy breeds do not have a significant difference at this indicator.

Holstein breed demonstrates the highest parameters of milk fat and protein. Among breeds of domestic breeding Ukrainian Black-and-White dairy breed has the best parameters. Ukrainian Red dairy breed in terms of fat slightly exceeds the corresponding figure of Ukrainian Red-spotted dairy breed.

At the same time, animals of Holstein breed have the lowest level of reproduction and productive longevity compared to other breeds. The best figures in terms of productive longevity shows Ukrainian Red-spotted dairy breed compared to the Holstein and Black-and-White dairy breed – 1234 to 1084 (p<0,01), 1234 to 1340 (p<0,05).

These data prove that Ukrainian Red-spotted and Red dairy breeds are characterized by the highest level of heritability, repeatability of milk yield for 305 days of lactation and number of  milk fat and the lowest – Ukrainian Black-and- White dairy breed, while Holstein breed occupies an intermediate position. Ukrainian Black-and-white dairy breed have the highest heritability and repeatability of the period between calving. Regarding to productive longevity there are not significant differences between breeds in terms of heritability.

Estimation of genetic correlations among traits in some differences between breeds as a whole shows a significant inverse relationship between milk production and reproduction of cows, while productive longevity weakly correlate with both milk production and from the period between calving. 

We defined and implemented the most appropriate conditions for Ukraine assessment model of bull-sires of dairy and dual directions of productivity by BLUP Animal Model.

Estimation of breeding and genetic parameters indicates the possibility of successful breeding both in terms of milk production, and in terms of reproduction and productive longevity.

The value of the genetic correlations between economically important signs points to the need to include indicators of reproduction and productive longevity in breeding index for transmitting the selection of bulls-sires.

Key words: dairy cattle, milk yield, milk fat, milk protein, period between calving, productive longevity, breeding value, BLUP, «animal model».