1. Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, P. R. China;
2. College of Informatics, Huazhong Agricultural University, Wuhan, P. R. China;
3. The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, P. R. China