[Zhang, Yong-gang;Yin, Yu-long] Chinese Acad Sci, Inst Subtrop Agr, Res Ctr Hlth Breeding Livestock, Hunan Engn & Res Ctr Anim & Poultry Sci,Key Lab A, Changsha 410125, Hunan, Peoples R China.^[Wang, Qi] Univ Guelph, Dept Anim & Poultry Sci, Guelph, ON N1G 2W1, Canada.^[Fang, Jun] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410125, Hunan, Peoples R China.