The global introduction of molecular genetic technologies into all areas of breeding began in the early years of the 21st century. The resulting transformations forever changed the original image of dairy cattle breeding that existed at that time. The application of modern breeding methods in recent decades has led to a significant increase in the productivity of dairy cattle. At the same time, recessive lethal alleles, called fertility haplotypes, began accumulating in cattle populations. The negative effect strongly affected both the economic efficiency of farms and the animals themselves: the level of productive longevity of cows decreased significantly. A haplotype is a section or segment of DNA that is passed on to offspring from parents as a single unit. Studying haplotypes in animal genomes is important to understand variations in their influence on phenotype formation and on the etiology and pathogenesis of diseases. In the presented review, we present genetic anomalies inherent in brown Swiss cattle. The study for their carriage is especially relevant for the Kostroma breed of cattle. Currently, 5 fertility haplotypes (SDM, SAA, SMA, Weaver, BH2) associated with embryonic and early postembryonic mortality at different stages are recorded in the Brown Swiss breed. We determine possible reasons for the spread of fertility haplotypes in cattle populations, namely: constant use in the practice of artificial insemination of bulls that are latent carriers of the mutation, a long-time interval from the emergence to the detection of the mutation, which is approximately 18–59 years. We note the key role of DNA diagnostics in the control and elimination of fertility haplotypes in the population of breeding cattle concentrated on the territory of the Russian Federation, as a consequence of genetic defects
Keywords
cattle, Cattle, Kostroma breed, reproductive ability, genetic defects, fertility haplotypes