1. College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan, PR China;
2. Department of Animal Production, Laboratory for Animal Nutrition and Animal Product Quality (LANUPRO), Ghent University, Melle, Belgium;
3. Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, PR China;
4. Department of Applied Biosciences, Ghent University, Gent, Belgium