Affiliation: | aDepartment of Infection Biology, Central Veterinary Institute, Wageningen UR, Lelystad, The Netherlands;bThe Roslin Institute, University of Edinburgh and R(D)SVS, Roslin, Midlothian, Edinburgh, United Kingdom;cInstitut National de la Recherche Agronomique, Unité ISP, Centre Val de Loire, Nouzilly, France |