1. Institute for Poultry Science and Health, Guangxi University, Nanning, China
2. Guangxi State Farm Yongxin Husbandry Group of Xijiang Co., Ltd., Guigang, China
3. Institute of Microbe and Host Health, Linyi University, Linyi, China
4. USDA, Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, Michigan, USA