Limited hybridization between domestic sheep and the European mouflon in Western Germany

Abstract

European mouflons (Ovis orientalis musimon) are Mediterranean sheep that were introduced worldwide as park and game animals during the last few centuries. Today, European mouflons are endangered in their natural refuge areas. Mouflons are able to interbreed with domestic breeds to form fertile hybrids of an intermediate phenotype. As some introduced mouflon populations were deliberately crossed with primitive domestic breeds to improve their hardiness and trophy size and as evidence of uncontrolled interbreeding exists, the alleged purity of most mouflon populations has been debated for decades. In this study, we developed a genetic test to separate pure bred mouflons and domestic sheep from their hybrids. We searched for hybridization using insertionally polymorphic endogenous retroviruses and a set of novel microsatellites. Three instances were found of domestic sheep alleles in a retrotype dataset out of 192 mouflons from Western Germany. Considering the combined outcome of microsatellite and retrotype profiling, the amount of hybridization is negligible. We assume that the selective hunting of animals that show signs of hybridization in their phenotype is responsible for the low number of hybrids.