Dynamics of dairy indicators for the period 2013-2021 in the breeding population of Holstein cattle breeding farm

The problem of formation of highly resistant, high-yielding stock is currently widely discussed. Control of the dynamics of dairy indicators within the framework of monitoring for several years allows on-farm improvement of breeding approaches and techniques. In order to study the level of realisation of the genetic potential of milk productivity of bulls-producers of different geographical and lineage origin and to identify leaders with the calculation of genomic forecast in the population of black-and-brown cattle, the population of first-calf heifers of Holstein breed with finished lactation, born in 2013-2021, numbering 5483 animals, three breeding lines R.Soering, V.B. Aidial and Montvik Chiftein, one of the breeding plants of the Leningrad Region was examined. The studied group of animals is represented by the daughters of 227 Holstein bulls. The level of genetic potential realisation was determined on the basis of genomic prediction of breeding value by milk yield, fat, protein. The Canadian bulls had a range of variability in the genomic forecast of over 430 kg, while the range of on-farm productivity of daughters was close to the genomic forecast and was 389 kg. The genomic prediction of US-born breeding bulls showed variability in milk yield of 80.3 kg. The genomic prediction of Gerald productivity was not significantly different from that of Alta Sustein (+308.7; +389 kg) with actual productivity of 12,933 kg and 13,613 kg, respectively. The genomic prediction for individual bulls was not confirmed by actual indicators and rotation or scrapping of outsider sires is necessary to maintain the trend of productivity growth.