The use of genomic assessment in improving the productive qualities of Holstein cows

Abstract. Purpose of the study is analysis of productive and reproductive qualities of the Holstein cattle of the Tyumen region in comparison with the leading American enterprises using genomic selection. Materials and methods. Zootechnical, statistical and economic methods were used. As part of the work, the tasks were solved to consider the growth and development of replacement young animals; the main indicators of reproduction of heifers and cows of the main herd were analyzed; the milk productivity of cows and first-calf heifers was estimated according to the primary accounting data; a zootechnical assessment of sires used in the economy was carried out; the results of the genomic assessment were compared with the actual milk production. The scientific novelty of the work lies in the fact that genotyping was carried out in the conditions of a large industrial complex, because the use of genomic evaluation was not widely used in farms in the Russian Federation. Research results. The indicators of the intensity of growth of replacement young animals grown in the conditions of the Evika-Agro enterprise correspond to the world standards of the breed, and in some cases exceed them. The intensity of growing heifers allows for earlier insemination, which also contributes to early calving - 98% of animals calve up to 25 months of age. Estimates of milk production are largely consistent with those of advanced farms in the United States. “Evika-Agro” LLC uses outstanding sires from the world’s gene pool to improve economically useful traits, thereby accelerating the rate of selection. Analysis of the genomic assessment showed a significant discrepancy between the genetic basis of milk production and the actual level of milk production. This is most noticeable in the lifetime earnings index (682) and the average increase in milk per lactation (916. 2 kg) between the worst and best heifers in the sample.