Genetic structure of cattle of the siberian branch by microsatellite loci

Molecular-genetic methods are essential tools for the utilization and conservation of animal genetic resources. These methods facilitate more efficient management and control of breeding programs within livestock production systems. For studying the genetic diversity of a population, the use of STR markers is relevant due to the high variability of repeats. This study presents a genetic characterization of a Holstein and Black Pied cattle population (n = 10233) in Western Siberia using 12 microsatellite loci (BM1818, BM1824, BM2113, ETH10, ETH225, ETH3, INRA023, SPS115, TGLA126, TGLA122, TGLA227, TGLA53). A total of 145 alleles were identified across all loci, with frequencies ranging from 0.00005 to 0.68961. The highest level of genetic diversity was observed at the TGLA122 locus (25 alleles) with an average number of effective alleles (Ne) of 4.5. The least polymorphic locus was BM1824 (7 alleles) with an average Ne of 3.27. The average observed (Ho) and expected (He) heterozygosity across all loci was 0.6. The highest variability was observed at the TGLA53 locus, with a Wright’s fixation index (Fis) of 0.161, indicating a heterozygote deficiency. A similar deficiency was observed at the BM1818 locus. All other loci exhibited a positive Fis, with the highest value observed at the ETH3 locus (-0.074), indicating an excess of heterozygotes. The average Fis across all loci was -0.02, suggesting a sufficient level of heterozygosity within the studied population. These findings provide valuable information for population studies and practical breeding programs aiming to manage genetic diversity and improve selection efficiency in this cattle population.