1. Institute of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, P.R. China
2. Department of Pharmacy, Tianjin Baodi Hospital, Baodi Clinical College, Tianjin Medical University, Tianjin 301800, P.R. China
3. College of Animal Science, Jilin University, Changchun 130062, P.R. China
4. Department of Animal Husbandry and Veterinary Medicine, Beijing Vocational College Agriculture, Beijing 102442, P.R. China