1. Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, P. R. China
2. College of Chemistry and Enviromental Science, YiLi Normal University, Yining 835000, P.R. China
3. College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, P. R. China