1. Department of Animal Science, Aarhus University, Foulum, Tjele, Denmark
2. Key Laboratory of Animal Disease-Resistance Nutrition and Feed Science, Ministry of Agriculture, P. R. China, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, China
3. Department of Obstetrics, Gynaecology and Reproduction Faculty of Veterinary science and Swine Reproduction Research Unit, Chulalongkorn University, Bangkok, Thailand
4. SEGES Danish Pig Research Center, Copenhagen, Denmark