1. College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
2. The State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
3. Institute of Grassland Research of CAAS, Chinese Academy of Agricultural Sciences, Hohhot, China
4. Gansu Runmu Bio-Engineering Co., LTD, Yongchang, China