Abstract
Two types of Polish local cold-blooded horses – Sztumski and Sokólski, covered by genetic resources conservation programs, were analyzed for founder’s contribution, genetic structure and inbreeding. In both populations, created in the early twentieth century, were used the same stallions, mainly Ardennes, Belgians and Bretons. The aim of the study was to analyze the genetic variability of Sztumski and Sokólski cold-blooded horses, using pedigree information. The reference population contained 2359 horses: 1129 Sztumski and 1230 Sokólski included in conservation programs in 2014. The data set consisted of a total of 12,821 ancestor pedigrees. The results showed that in the analyzed population the number of founders was 1139 for Sztumski and 1118 for Sokólski horses; effective population size and effective number of founders were 688.8; 156.9 and 704.5; 111.4, respectively. The mean coefficient of inbreeding was 1.54 for Sztumski and 1.56 for Sokólski horses. In the gene pool the most important contribution was of Ardennes horses (43.67% in Sztumski and 46.82% in Sokólski horses), followed by Belgian horses (18.32% and 9.3%, respectively). The most important ancestors in both populations were Ardennes sires Roll-tan 699 and Gustaw 2807, and German cold-blooded sires Elbgang 1504 and Bär.