1. Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, P. R. China
2. Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiujiang, Jiangxi 332000, P. R. China
3. College of Biology & Pharmacy, Yulin Normal University, Yulin 537000, P. R. China
4. Beijing General Station of Animal Husbandry, Beijing 100101, P. R. China
5. Department of Biomedical Engineering, Shenzhen University, Shenzhen 518060, P. R. China