PSI-B-25 - Assessment of the genetic resources of Russian local cattle breeds by genome-wide SNP analysis

Russia is reach by local cattle genetic resources, which are well adapted to the different environment. However, the modern cattle husbandry tends to the replacing the local cattle breeds by highly productive commercial breeds, which can lead to the decline of genetic diversity. The aim of our work was to estimate the genetic identity of five Russian local cattle breeds, including Yaroslavl (n = 52), Kholmogor (n = 26), Istoben (n = 21), Tagil (n = 26), and Black-and-White (n = 44). The Holstein breed (n = 49), which is actively used for improvement of above breeds was included in the study for comparison. The genotyping was performed using GGP Bovine 150K Array (Illumina, San Diego, CA, USA) and more than 112000 autosomal SNPs passed through the quality control and were selected for the analysis. We observed the significant excess of heterozygotes in four studied breeds (the values of unbiased inbreeding coefficient were varied from -0.009 to -0.022), except for Black-and-White breed. The effective population size (Ne) for Istoben, Tagil and Kholmogor breeds was declined until present, while Holstein and Black-and-White breeds showed the increase of Ne values starting at 5 generations ago. The Black-and-White breed was the closest to the Holsteins (Fst=0.014), while the Yaroslavl breed was the most distant (Fst=0.115). The highest ratio of Holstein specific genomic components was shown for Tagil (18.79%) and Black-and-White (59.73%) breeds. Our results indicated replacing the part of aboriginal genomic components in several Russian local cattle breeds by Holstein specific components. The comprehensive strategies for conservation of the Russian local cattle breeds are needed to avoid the further decline of genetic diversity of these valuable national animal genetic resources. The study was funded by the Ministry of Science and Higher Education of the Russian Federation within theme 0445-2019-0024.