Bovine rotavirus strain 678, which was originally isolated from a diarrheic calf in Great Britain, was found to belong to a newly established serotype 8 prototype strain HRV 69M) by plaque reduction neutralization (PRN) assay. Bovine rotavirus strain ID, which was a "supershort" electropherotype, was found to belong to serotype 6 (prototype bovine rotavirus NCDV strain which has a "long" electropherotype) by PRN assay. Bovine rotavirus strain B223 was shown, by a one-way cross-neutralization assay, to be distinct from any of the 9 established serotypes.