Breeding effect of return crossing of cattle

To increase the efficiency of dairy farming, a demand arose to change the breeding programs for dairy cattle breeding in the Omsk Region, which should be aimed at reducing the proportion of blood in the offspring of improving imported breeds. The purpose of the research is to evaluate the effectiveness of breeding when including return crossing in breeding programs. The object of research was a population of dairy cows amounting to 3,764 heads bred in the Omsk Region. It was found that the heritability of milk yield in cows selected for return crossing is higher than the average for the herd by 0.02. The breeding differential of low-bred black-and-white cows was +1,524 kg of milk, which is 203 kg more than that of cows with a blood content of more than 70%. The calculations show that, while maintaining the conditions of keeping and feeding, due to the selection of cows in the breeding group, taking into account the blood type of the improving breed, the total milk yield for 3 lactation in the next generation will increase by 449.5-579.1 kg of milk. The maximum increase in productivity at the return crossing should be expected from cows with low Holstein blood content. The greatest genetic potential of productivity is expected in herds of black-and-white cattle with 7,037-7,283 kg. For the red steppe breed, the expected productivity of the first-generation crossbreeds amounts to 5,942-6,608 kg, which is a high indicator for this breed. Return crossing in the breeding programs of the dairy cattle of the Omsk Region will create improved genotypes of highly productive animals that can fully realize their genetic potential in local conditions; the breeding effect will amount to +450 kg or more.