1. De-Zhang Lu:
Department of Veterinary Surgery, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P.R.China
2. Sheng Jiang:
Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin, P.R.China
3. Shi-Ming Yu:
Department of Veterinary Surgery, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P.R.China
4. Hong-Gang Fan:
Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin, P.R.China