1. College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, P. R. China
2. Department of Obstetrics & Gynaecology; Li Ka Shing Institute of Health Sciences; School of Biomedical Sciences; and The Chinese University of Hong Kong-Sichuan University Joint Laboratory for Reproductive Medicine, The Chinese University of Hong Kong, Hong Kong, China
3. Department of Physiology and Pharmacology, Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University, Barishal 8210, Bangladesh
4. Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Northeast Agricultural University, Harbin 150030, P. R. China
5. Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Northeast Agricultural University, Harbin 150030, P. R. China