Key Laboratory of Bovine Low?Carbon Farming and Safe Production Institute of Animal Nutrition Sichuan Agricultural University Chengdu 611130 P.R.China;
Faculty of Veterinary and Agricultural Sciences The University of Melbourne Victoria 3647 Australia;
Angel Yeast Co. Ltd. Yichang 443000 P.R.China;
Department of Animal Nutrition Bangladesh Agricultural University Mymensingh 2202 Bangladesh;
Department of Animal Sciences Jomo Kenyatta University of Agriculture and Technology Nairobi P.O.Box 62000?00200 Kenya;