1. Jiang Su Provincial Key Laboratory of Veterinary Bio-pharmaceutical High-tech Research, Jiangsu Agri-animal Husbandry Vocational College, Taizhou, China.
2. Department of Veterinary Diagnostic & Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
3. Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.
4. College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA.
5. Department of Animal Science, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.