Affiliation: | 1.Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, SE-750 07, Uppsala, Sweden;2.Swedish Animal Health Service, Kungsängens gård, SE-753 23, Uppsala, Sweden;3.National Veterinary Institute, SE-751 89, Uppsala, Sweden;4.Department of Clinical Sciences, Division of Reproduction, Swedish University of Agricultural Sciences, P.O. Box 7054, SE-750 07, Uppsala, Sweden |