1. MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, P. R. China
2. Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, P. R. China
3. College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, P. R. China
4. College of Life Science and Technology, Yancheng Teachers University, Yancheng, P. R., China