| seroconversion to bovine viral diarrhoea virus and infectious bovine rhinotracheitis virus in dairy herds of michoacan, mexico. | bovine viral diarrhoea virus (bvdv) and infectious bovine rhinotracheitis virus (ibrv) are important viral diseases around the world. the objective of this study was to estimate the incidence of seroconversion to bvdv and ibrv and to identify associated risk factors in dairy herds of michoacan, mexico. the longitudinal study included 62 herds and ran from december 2001 to november 2002. the total number of animals enrolled and completing the study were 392 and 342 animals for bvdv and 925 and 89 ... | 2010 | 19685278 |