Tests carried out under the Gwaredu BVD scheme indicate that more than a quarter of Welsh beef and dairy herds are infected with Bovine Viral Diarrhoea (BVD). This demonstrates a clear need for livestock farmers to take appropriate action to protect their herds from the hallmark symptoms of BVD infection which include reduced productivity as a result of immunosuppression and reproductive failure.
Gwaredu BVD is an industry led programme (funded by the Welsh Government Rural Development Programme (RDP)) to eradicate BVD in Wales. The scheme gives Welsh livestock farmers access to up to £500 of funding to work with their vet to diagnose if their herd has been exposed to the virus, and to seek and remove any infected animals.
In the scheme’s first five months over 3,000 herds have been tested. “Of these, more than 25% have tested positive,” explains John Griffiths, manager of the Gwaredu BVD scheme. “That means as many as 750 of the herds tested to date are potentially underperforming as a result of infection. Whilst the total number of affected herds in Wales is unknown, it is clear that farmers must act now to stop the disease from spreading and to reduce its effects.”
BVD has the potential to cause significant financial losses as a result of poor fertility, reduced milk yields, low daily live weight gains, fever, diarrhoea and respiratory problems.
“On farm, this means more calves suffering from conditions such as pneumonia or scours and fewer calves being conceived,” John continues. “This can cost beef herds as much as £45 per cow per year and as much as £15,000 per year for an average 130-cow dairy herd.”
Under the Gwaredu BVD scheme, all beef and dairy herds in Wales are entitled to free screening to test for the presence of the BVD virus: farmers can blood test up to five unvaccinated animals (ranging from 9 to 18 months of age) from each management group within the herd for a maximum of three years. If these tests positively identify the BVD virus, an additional £500 is available for farmers to work with their vet to find any Persistently Infected (PI) animals.
“The successful eradication of BVD from an infected herd is dependent upon accurately and rapidly identifying all PI animals,” says Dr Sigrid Stoop of Allflex and one of the architects of Belgium’s successful BVD eradication scheme. “Once identified, these infectious animals should be isolated and culled before they can spread the disease to the rest of the herd.”
The simplest, most cost-effective way of identifying PI animals is to use Tissue Sampling Tags (TSTs) as part of the normal tagging process for all newborn and recently purchased animals. “Testing in this way is a cheap and easy method of identifying any ‘dirty’ animals,” Dr Stoop adds, “and is more reliable than vaccination alone as this can only protect a BVD-free herd and cannot cure animals which are already infected.”
For more information about Bovine Viral Diarrhoea, or to access funding from the Gwaredu BVD scheme, farmers should speak to their farm vet.