1. Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
2. School of Veterinary Medicine, Wollega University, PO Box: 395, Nekemte, Ethiopia
3. School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester M13 9PL, UK