Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing 100193, P.R.China;
College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109, P.R.China;
Institute of Grassland Science, China Agricultural University, Beijing 100193, P.R.China;
Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing 100193, P.R.China;
Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing 100193, P.R.China;
Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing 100193, P.R.China;
Institute of Grassland Science, China Agricultural University, Beijing 100193, P.R.China;
Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing 100193, P.R.China;
Institute of Animal Sciences, Chinese Academy of Agricultural Science, Beijing 100193, P.R.China;