1. University of Copenhagen, Faculty of Health Sciences, School of Veterinary Medicine and Animal Science, Dyrlægevej 16, 1870 Frederiksberg C, Denmark
2. University of Copenhagen, Department of Public Health, Section of Biostatistics, Øster Farimagsgade 5 opg. B, 1014 København K, Denmark
3. University of Copenhagen, Department of Plant and Environmental Sciences, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark