[1] Nanjing Agr Univ, Inst Ensiling & Proc Grass, Coll Agro Grassland Sci, Nanjing 210095, Peoples R China
[2] Univ Cattolica Sacro Cuore, Fac Agr Food & Environm Sci, Dept Anim Sci Food & Nutr DIANA, I-29122 Piacenza, Italy
[3] Tibet Acad Agr & Anim Husb Sci, Inst Anim Sci, Lhasa 850000, Peoples R China