The impact of bovine viral diarrhoea virus on fertility in cattle and the protective effect of vaccination

Bovine viral diarrhoea virus (BVDV) infection is associated with significant reproductive losses in cattle through the detrimental impact of both persistent and transient infection on breeding females and males. The pathology within the reproductive tract is well described, although the mechanisms that lead to reproductive failure have yet to be fully unravelled. Prolonged shedding of virus following acute infection of bulls in both the peri- and post-pubertal periods has been observed, although the significance of this in relation to reproductive failure and the spread of infection has yet to be fully explored for the UK situation. Infection and recovery lead to an immune state in the female that is protective against breeding failure and generation of persistently infected calves. Vaccination using either of the two vaccines licensed for the control of BVDV infection in breeding cattle in the UK has been shown to be protective against fetal infection. In the UK where regional and herd level eradication of BVDV is progressing against a background of endemic infection, vaccination would appear to offer stopgap mitigation against reinfection until such times as national eradication is achieved.