1. College of Grassland Science, Gansu Agricultural University, Lanzhou, China.
2. Key Laboratory of Grassland Ecosystem, Ministry of Education, Pratacultural Engineering Laboratory of Gansu Province, Sino-U.S. Center for Grazingland Ecosystem Sustainability, Lanzhou, China.
3. Qinghai Academy of Animal Husbandry and Veterinary Sciences, Qinghai University, Xining, People's Republic of China.
4. Key Laboratory of Superior Forage Germplasm in the Qinghai–Tibetan Plateau, Qinghai Academy of Animal Science and Veterinary Medicine, Xining, China.