1. Animal Welfare Science Centre, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, VIC, 3010, Australia
2. Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-1870 Frederiksberg C, Denmark
3. Pig Research Centre, Danish Agriculture and Food Council, Copenhagen, 1609 Copenhagen V, Denmark
4. School of Animal and Veterinary Science, University of Adelaide, SA, 5371, Australia