[1] Tokyo Univ Agr & Technol, Fac Agr, Dept Vet Med, Lab Vet Hyg, Fuchu, Tokyo 1838509, Japan
[2] Gyeongsang Natl Univ, Coll Vet Med, Chinju 660701, Kyeongsangnamdo, South Korea
[3] Mitsui Sugar Co Ltd, Res Lab, Chigasaki, Kanagawa 2530042, Japan
[4] Natl Agr& Biooriented Res Org, Natl Inst Anim Hlth, Tsukuba, Ibaraki 3050856, Japan