* Financially supported by National Basic Research Program of
China (Project No: 2004CB117500) and Young Scientist Award
(Project No: 2004DA125184-0808) from the National Key
Laboratory of Animal Nutrition.
** Corresponding Author: Qiugang Ma. Tel: +86-10-62732774,
Fax: +86-10-62732774, E-mail: maqiugang@gmail.com
2 College of Bioengineering, Henan University of Technology,
Zhengzhou, 450001, China.
Received February 8, 2009; Accepted April 13, 2009