The main purpose of the study was to establish the genetic variety on the population of trotter horses in Bulgaria since there had been no such research.
The research involved 55 trotter horses included in the Stud book. We used 6 microsatellite markers (AHT4, AHT5, ASB2, HMS1, HMS2, HMS3). We used the POPGENE v.1.31 program for the estimation of the main parameters characterizing the allele varieties in the observed loci: number of alleles (effective and average) and their frequency, expected (He) and observed heterozygosity (Ho).The result obtained from the research showed that the highest polymorphism was shown by loci ASB2 and HMS2 with 8 alleles, and locus HMS1 had the lowest number of alleles (5). The P allee was of the highest frequency – 0.4455 in locus HMS3, the lowest allele was I (0.0091) in loci HMS2 and AHT5. The greatest variation was observed in locus HMS3 – from 0.0182 to 0.4455.
The observed heterozygosity varied from 0.6727 in locus AHT4 to 0.8545 in ASB2. The lowest expected heterozygosity was 0.7091 in locus HMS1, the highest – 0.8499 in locus ASB2. The high level of heterozygosity in all obtained loci indicated high genetic diversity in the population of trotter horses in Bulgaria.