T. Yun, H. P. Chen, J. G. Hua, B. Yu, L. Chen, Z. Ni, W. C. Ye, C. Zhang
1 Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021,
2 College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai•an 271018, China