Analysis the spread of inbreeding in herds black-and-white and Holstein cattle Orel region

Inbreeding is one of the challenges the present-day cattle breeding faces due to the fact that many outstanding sires are relatives. To study this problem, the authors of the article monitored how widely inbreeding occurred in dairy herds in the Orel Region. Classical zootechnical research methods were used in the work, and the inbreeding coefficient was determined by the Wright-Kislovsky formula. Agrofirma Mtsenskaya, Kurakinskoe, Slavianskoye, Krasnaya Zvezda, Farm named after Michurin, Streletskoye and Yupiter are the Orel Region's farms where the authors have studied the spread of inbreeding in various degrees of kinship. The authors established that 625 cows out of 3,013 were inbred to some extent (20.74% of the total number of animals). Among the inbred livestock, the most prevalence of inbreeding was found in cows which had inbred fathers in their pedigrees - 257 heads (8.5% of the total number of livestock). Moderate kinship was represented by 211 heads, which amounted to 7.0% of the total livestock. Inbreeding was a rare thing in some herds such as those of Agrofirma Mtsenskaya (4.97%) and Streletskoye (6.42%). Inbreeding gave contradictory results on the increase in milk productivity of first-calf cows. In the Farm named after Michurin, a negative effect of inbreeding on the calving results was obtained; in particular, the percentage of stillborn calves was 4.9. Based on the results of the research, it was suggested to develop an effective system for monitoring the spread of inbreeding and its consequences in the population of dairy cattle in the Orel Region.