Institution: | 1. Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, P.R.China;Department of Veterinary Surgery, College of Veterinary Medicine, Northwest Agricultrue and Forestry University, Yangling 712100, P.R.China 2. Department of Veterinary Surgery, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, P.R.China |