1. College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, P.R. China.
2. College of Animal Science and Technology, Changchun Sci-Tech University, Shuangyang, P.R. China.
3. Alashankou Entry Exit Inspection and Quarantine Bureau, Alashankou, P.R. China.
4. College of Veterinary Medicine, Northwest A&F University, Yangling, P.R. China.
5. College of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou, P.R. China.
6. College of Basic Medicine, Mudanjiang Medical College, Mudanjiang, P.R. China.