Bovine viral diarrhoea (BVD)

Part of: AFBI Cattle Health Scheme

Area of Expertise:

BVD programmes within AFBI Cattle Health Scheme

Agent/cause

  • BVD is caused by a virus, bovine viral diarrhoea virus (BVDV)

Disease

Infection can result in a wide range of clinical signs including:

  • Weakening of the immune system, leaving cattle more susceptible to other infections
  • Scours and pneumonia in calves
  • Reproductive problems, including failure to conceive, abortion and birth defects in older cattle
  • Calves that survive infection during early pregnancy are born persistently infected (PI) with the virus. Many will develop a fatal condition called mucosal disease in the first two years of life

Introduction and spread

  • Purchase of PI cattle (possibly as unborn calves in pregnant cattle) is the most important means of introduction.
  • PI calves are the main transmitters of virus to other cattle.

Impact

  • Economic losses can be very high.
  • Persistently infected bulls are excluded from AI centres due to the presence of BVDV in their semen.
  • Possible future restriction on live exports.

Control programme

  • Test programme using blood and milk samples.
  • Identification and removal of PI animals is recommended, coupled with biosecurity measures to prevent re-infection.

​​Biosecurity

  • Vaccination with killed vaccine may be used within any of the programmes, but it is mandatory in the Vaccinated Monitored Free (VMF) program.
  • Double fencing 3 meters wide mandatory for the BVD accredited programme. Not mandatory on the VMF programme.
  • Added animals from non-accredited herds must be placed in isolation and tested for BVD

Test types

  • Bulk tank milk test (BTM)
  • First lactation test (FLT): Individual milk samples from all first lactation cows
  • Check test:  test for BVD antibodies in sentinel group of the 5 homebred cattle in each separately managed group of cattle aged 9-18 months. See technical document for details AFBI Cattle Health Scheme : Certification Standards

These are used in a structured way in: