1. Graduate School of Animal and Food Hygiene; Obihiro University of Agriculture and Veterinary Medicine; Obihiro Japan
2. Field Center of Animal Science and Agriculture; Obihiro University of Agriculture and Veterinary Medicine; Obihiro Japan
3. Department of Clinical Veterinary Science; Obihiro University of Agriculture and Veterinary Medicine; Obihiro Japan
4. Department of Veterinary Medical Science; The University of Tokyo; Tokyo Japan