Efficiency of breeding value genomic assessment of Holstein stud bulls in comparison with the assessment of the offspring quality

Abstract

A comparative analysis of the genomic assessment results of Holstein breed stud bulls and their assessment on the offspring quality in the conditions of the Udmurt Republic was carried out. To analyze the efficiency of using stud bulls assessed by different methods, data from farms included in the ranking of the top 20 enterprises in terms of milk yield per cow for 2019-2020 were used. A high indicator of the complex LPI index (over 2500) was obtained in three bulls at the beginning of the assessment, by the end of the assessment there were two bulls left - J. Koln-M 11087837 and Super 64131037. The outsiders of the LPI ranking were stud bulls Parlament 52800347 and Patrik 51660096. The indicators of the complex LPI index are at a decent level for all analyzed stud bulls. It should be noted that stud bulls, which had the least change in the LPI index from April 1, 2014 to December 1, 2017, performed well. Bulls, which initially had overestimated results on this indicator, subsequently gave a sharp decline in the LPI index. The value of milk productivity of the evaluated stud bulls' daughters ranged from 5930 to 6415 kg, the mass fraction of fat in milk - from 3.79 to 4.02%, protein - from 3.06 to 3.11%. In most cases, the genomic assessment does not accurately reflect the change in the productive quality of stud bulls' daughters. But in the case of a predicted change to a positive or negative side in the genome, it is also confirmed by the results of assessing the offspring quality, that is, if a bull is predicted to have a sharp decrease in milk yield, then negative indicators are observed according to the “daughter-peer” method.