مشخصات پژوهش

Genetic diversity in Kermani sheep was assessed using the pedigree records by quantifying demographic parameters under pedigree analysis via studbook information collected from 1990 to 2011 in the breeding station of Kermani sheep, Sharebabak, south-east of Iran. Lambs born during 2008–2011 were considered as reference population. The mean generation interval from four pathways was 4.48 years. The generation interval in sire-progeny pathway was longer than dam-progeny. Mean inbreeding and average coancestry for reference population were computed as 0.51% and 1.04%, respectively. Average equivalent complete generation, as a measure of pedigree completeness, was 2.22. Effective population size was estimated to be 100 from the individual rate in coancestry and 120 from the individual increase in inbreeding. Genealogical parameters estimated based on probabilities of gene origin including the effective number of founders, the effective number of ancestors, the effective number of founder genomes (founder genome equivalents) and the effective number of non-founder genomes for reference population were estimated as 149, 72, 48 and 71, respectively. Approximately, 50% of total genetic variation was explained by the 33 most influential ancestors, with a maximum individual contribution of 4.8%. The average relationship coefficient among active rams and the average relationship coefficient between active rams and ewes during the last 4 years (2008–2011) were 0.11 and 0.05, respectively. The results indicated that although some evidences on bottlenecks and genetic drift during recent years were identified in the studied population, a relatively considerable genetic variability exists in this population.