Study of genetic diversity of Dagestan Mountain cattle based on STR-markers

Сheap pasture fodder and a long grazing season are favorable for cattle breeding in the Dagestan Republic of Russia. However, specific natural and geographical conditions including mountain terrain, hypoxia, and high humidity slow down intensification of cattle breeding in this region. Thus, maintenance of genetic diversity of local cattle breeds, which fit well into specific environments, is of special importance for mountain ethnic communities. Dagestan Mountain cattle is local breed developed by improving native cattle with Swiss Brown, Kostroma and Kian breeds. This breed has valuable biological traits including strong hooves, stamina, and adaptability to extreme mountain conditions. Only 650 heads of Dagestan Mountain cattle were registered in 2020 and the “breed-purity” of them is questionable. In this study, we aimed to characterize allele pool and to assess genetic diversity of modern Dagestan mountain cattle using STR-markers. The sample included 32 individuals of Dagestan Mountain cattle collected from private owners in the mountain villages of Dagestan during a scientific expedition. A total of 130 samples from other cattle breeds including Red Steppe, Brown Swiss, Holstein, and Simmental was used as comparison groups. The genotypes for 11 STR loci recommended by ISAG were obtained using a genetic analyzer ABI3130xl (Applied Biosystems, USA). We observed the high level of genetic diversity in Dagestan Mountain cattle as revealed by calculations of the mean number of alleles per locus (6.82 compared to 4.79-5.82 in other breeds) and observed heterozygosity indices (Ho = 0.73, that was higher comparing to the other breeds (Ho = 0.69) excluding Simmentals and Brown Swiss (Ho = 0.74). Based on STRUCTURE results, the individuals with low level of admixture with other breeds were found within Dagestan Mountain cattle, which can be considered as candidates for using in germ plasm conservation programs.