[1]College of Animal Science and Technology;
China Agricultural University;
Beijing 100193;
P.R. China;
[2]Institute of Animal Science;
Chinese Academy of Agricultural Sciences;
Beijing 100193;
P.R.China;
[3]School of Chemistry & Chemical Engineering;
Ningxia University;
Yinchuan 750021;
P.R. China;
[4]Institute of Animal Science;
Hubei Academy of Agricultural Sciences;
Wuhan 430064;
P.R.China;