1. State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
2. Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
3. Department of Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, USA
4. Department of Animal Science, Division of Agriculture, University of Arkansas, Fayetteville, Arkansas, USA