testing of bulk tank milk from northern ireland dairy herds for viral rna and antibody to bovine viral diarrhoea virus. | bulk tank milk samples collected from 929 northern ireland dairy herds were classified according to their geographical location, somatic cell count and milk yield. each sample was tested by elisa for antibody levels to bovine viral diarrhoea virus (bvdv) and the herds were assigned to four groups with increasing antibody levels. in nine herds (1 per cent) no antibodies were detectable in the milk samples (group 1) and they were detectable at low levels in the milk from 90 herds (9.7 per cent, gr ... | 2001 | 11558660 |