Department of Breeding and Genetic Resources, Institute of Farm Animal Genetics, Neustadt, Germany. cong.chi@fli.bund.de|Department of Breeding and Genetic Resources, Institute of Farm Animal Genetics, Neustadt, Germany. cong.chi@fli.bund.de|Department of Breeding and Genetic Resources, Institute of Farm Animal Genetics, Neustadt, Germany. cong.chi@fli.bund.de|Department of Breeding and Genetic Resources, Institute of Farm Animal Genetics, Neustadt, Germany. cong.chi@fli.bund.de