Genetic Load of Mutations Causing Inherited Diseases and Its Classification in Dairy Cattle Bred in the Russian Federation

This review addresses the concept of genetic load from point view molecular genetics, development and efforts in selective breeding. As typical examples, assessment animals Holstein breed its high-blooded crossbreeds is considered for mutations that cause three inherited diseases: bovine leukocyte adhesion deficiency (CD18 locus), complex vertebral malformation (SLC35A3 brachyspina (FANCI locus). The reasons their occurrence accumulation breeding herds black-pied genealogical root are discussed. These include an intense artificial-selection bulls cows highly productive intensive sale (within between countries) material (animals, semen, embryos) a small population sires countries with high level dairy-cattle development. There founder effect when source mutant-allele spread prominent sire. For example, greatest contribution to mutant alleles CD18G, SLC35A3T FANCIBY was made by descendants closely related bulls. A genogeographic generalization mutation world Russia provided these hereditary-disease loci and, includes total 31 where were detected. genetic-load classification other given. both recessively (CD18G, SLC35A3T, FANCIBY) codominantly (CSN3A, CSN3C, CSN3E, CSN2A1, CSN2B). Genetic classified into following types: mutational, segregation, substitutional, immigration. each these, examples given explain occurrence. Overall, it can be concluded phenomenon industrial dairy cattle requires special attention creating healthy livestock obtaining high-quality products.