1. School of Life Sciences; Nanjing University; Jiangsu P. R. China
2. Nanjing University Ecology Institute of Changshu; Changshu Jiangsu P. R. China
3. Institute of Animal Science; Jiangsu Academy of Agricultural Sciences; Nanjing Jiangsu P. R. China
4. Senpro Mechanical and Electrical Co., Ltd.; Shanghai P. R. China