Genealogical analyses in open population of Silla Argentino horses belonging to the national police of Colombia

This study aimed to evaluate population parameters, genetic diversity and identify the ancestors with the highest genetic contribution of an open population of Silla Argentino horses in Colombia using pedigree data. 508 horses born between 1998 and 2018 were evaluated, called reference population (RP). The ancestors of the RP were added, defining the total population (TP) whit 1,861 horses born since 1905. Population parameters were estimated, including inbreeding coefficient (F), effective population size (Ne), effective number of founders (fe), ancestors (fa), and founder genomes (fg) and generation interval (GIN). The GIN was 10.1 (TP) and 7.7 (RP) years. The estimate of F for the RP was 0.3%, indicating control in mattings. The Ne was 317 (RP) and 179 (TP). The probability of genes origin indicated values for fe, fa and fg of 386, 187 and 351 (TP), and 161, 64 and 56 (RP), respectively, evidencing a reduction of genetic variability in the RP. Half of the genetic variation in the equine population studied was explained by 40 ancestors. The results show loss of genetic diversity in the RP and the genetic contribution of the ancestors suggests the need to increase the number of stallions for breeding and guide mating to increase genetic diversity in the new generations of Silla Argentino horses of the Colombian National Police