Genetic diversity analysis in the reproductive nuclei of heavy breeds of the National Equine Promotion Plan by using microsatellite loci

In Chile, the National Equine Promotion Plan for Agriculture (PNFE) aims to generate Chilean draft horses through absorbent crosses between native crossbred mares and fine heavy draft stallions belonging to the Chilean Army. The goal of this study was to characterise by microsatellite DNA analysis the genetic variability within the purebred core: Ardenes (20), Breton (23) and Percheron (20). The individuals were analysed using 16 microsatellite locus (VHL20, HTG4, AHT4, HMS7, HTG6, AHT5, HMS6, ASB23, ASB2, HTG10, HTG7, HMS3, HMS2, ASB17, HMS1 and CA425). Molecular genotyping showed that the total number of alleles for several locus varied from 1 to 7; 3-6 and 2-7, according to each breed, with an average of 4.3; 4.8; 4.8 alleles per locus for the Ardennes, Breton and Percheron, respectively. Mean values of observed heterozygosity (H-o) were 0.63; 0.72 and 0.64 for each race, respectively. In all three cases, the mean observed heterozygosity was higher than expected heterozygosity (H-e) and Nei index. Heterozygosity and fixation index analysis revealed that the three cores showed a low level of inbreeding.