1. Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, Sichuan, China
2. Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu City, Sichuan, China
3. Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, Sichuan, China
4. Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, Sichuan, China