Cheng Suo, Yeshi Yin*, Xiaona Wang, Xiuyu Lou, Dafeng Song, Xin Wang and Qing Gu*
* Corresponding authors: Yeshi Yin yinyeshi@126.com - Qing Gu guqing2002@hotmail.com
BMC Veterinary Research 2012, 8:89 doi:10.1186/1746-6148-8-89