Prevalence of bovine viral diarrhoea (BVD) in Scotland has fallen to its lowest levels since a plan to eradicate disease began.
Since its introduction in September 2010 the plan, now entering its fourth phase, has seen the level of herds testing negative rise from 60% to 85% by April 2015.
Scottish borders vet Iain McCormick from Galedin Veterinary put this down to vaccination compliance, improved biosecurity and the early identification and culling of persistently infected (PI) cattle – an essential step towards eradication.
“There are great tools in the box, but they must be used properly.
“Read vaccine data sheets and store them correctly.
“Identify risks and plan double fencing ahead – nose to nose contact is a really easy way to spread the virus,” he said.
The phase four enhanced testing, which began on 1 June, has four key rule changes aimed at actively changing not-negative herds, which are herds that have had exposure and show a level of antibodies in testing into negative.
But those farmers with BVD negative status should not become complacent, warned Mr McCormick. He urged farmers to look up the BVD status of any Scottish animals before purchase at www.scoteid.com.
“If you are BVD negative, keep that status and guard it with your life, don’t get in a position where you’re not-negative, as it may take years and rigorous testing to regain BVD-free status.”
Key BVD rule changes
- Animals for sale for further breeding or fattening from a not-negative herd must not leave the farm until they have individually blood tested negative. Those going straight to slaughter do not require testing.
- In a negative herd, any animals joining from an untested herd must be isolated and tested.
- Year round calving dairy herds must test every six months – this must include a minimum of 10 calves aged between nine and 18 months from each separate group. Separate groups are formed of animals which have nose to nose contact with each other.The youngest and five oldest unvaccinated calves within each group must be tested.
- Bulk milk antibody testing has been removed as an annual testing option, though it can still be a useful monitoring tool for herds never exposed to BVD. Now farmers can either use check-tests (blood testing for antibodies in unvaccinated animals) or ear tag and testing / blood sampling for the BVD virus.
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