Comparative evaluation of the breeding value of Holstein bulls-producers

Abstract

Modern dairy cattle breeding efficiency is largely determined by the strategy of choosing a producer for herd reproduction, which determines the growth rate of herd productivity for the next 3 to 5 years. According to the results of 2022, there are 20 organisations in the Sverdlovsk region with milk production per feed cow of more than 9 thousand kg, including 10 farms with milk production of more than 10 thousand kg. The best farm in the region, APC “Kilachevsky”, produced an average of 12829 kg of milk for each of 3000 cows. Two record-breaking cows were milked there, each of which yielded more than 21 tonnes of milk for a standard lactation. Thirty-four breeding bulls were included in the study. As a result of their evaluation, it was found that in bulls whose genomic breeding value for milk yield exceeded 1000 kg of milk 80.0% of producers were actual improvers for this trait, and in bulls with low genomic breeding value for milk yield (0-99 kg) only 25.0% of producers were actual improvers. Bulls with a negative breeding value for milk production in 66.6 percent of cases turned out to be actual improvers. In terms of protein content in milk, the dependence is similar, the higher the genomic value of the sire according to MDB, the more bulls actually have a positive effect on the protein-milk content of daughters (Tables 3,4). However, the number of sires that confirmed genomic breeding value for protein-milk yield is much less than for milk yield. For milk yield, 17 sires out of 34 (50.0%) received confirmation of breeding value, and for protein-milk yield only 11 (32.0%).