1 Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, College of Life Sciences, Hunan Normal University, Changsha 410081, China.
2 College of Animal Science, South China Agricultural University, Tianhe District, Guangzhou 510642, China.
3 Department of Animal Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.