Herd health testing for BVD
Bovine Viral Diarrhoea (BVD) is more common in dairy herds than beef, which is a problem for the dairy sector because BVD reduces fertility and therefore hits lifetime milk production. It also increases abortions, calf illness and mastitis levels.
By far the main source of BVD is the PI (persistently infected animal) which is born infected and produces massive quantities of virus for its entire life. PIs quickly infect unprotected cattle by direct contact or indirectly via unwashed equipment, vehicles, or clothing.
They may look perfectly healthy, but PIs are a continuous risk to the rest of your herd: Pls should be removed from the herd immediately.
The most effective way to detect BVD in a herd is looking for exposure to BVD virus by measuring antibody levels in bulk milk, individual cow milk or blood samples from cows.
Identifying persistently infected cattle is done by using either ear notch tissue tags, blood tests or screening the bulk milk for the possible presence of a PI with a PCR test. Money spent on testing and prevention measures (e.g. vaccination, double fencing) is recouped in increased milk production, improved calf survival and reduced antibiotic costs.
For dairy farmers who wish to show cattle, the requirement is increasing to provide proof of either the accredited BVD free status of the animal’s herd of origin into which it was born, or the individual animal’s BVD virus negative test result prior to the event. If the animal isn’t tested for BVD and the herd isn’t part of a BVD accredited scheme you need to act now and test.
For information on testing for BVD call CIS on 01923 695319 or watch the CIS BVD webinar at https://youtu.be/aiPPJZMrmyE
Amanda Wilkes is Cattle Information Service (CIS) area manager
