The Scottish bovine viral diarrhoea (BVD) eradication scheme is now well under way. With the February 1 deadline passed, all keepers of breeding cattle will have performed some form of screening test.
For most beef herds, this will have been in the form of the simple check test – testing five calves between nine and 18 months old in each management group for an antibody to see whether or not BVD has circulated in that group of cattle.
In our practice area, roughly 90 per cent of herds have tested negative, leaving only 10 per cent either positive or inconclusive (officially termed “not negative”). This is much lower than the 40% of Scottish herds that are said to be infected. Well done Borders farmers.
Herds with positive tests will be starting the process of eradication: testing and removing persistently infected (or “PI”) animals. These are the virus carriers – infected for life and continuously spreading the virus. Once PI animals are found they should be culled. Keeping PI calves in an attempt to get them fattened is a bad idea – they will be a constant source of virus, and inevitably the majority of PI’s will die from the disease before reaching finishing weight.
For negative herds, the onus is now on protecting that valuable negative status and avoiding a costly breakdown.
l Don’t buy in BVD. Buy from CHECS accredited free herds or test new cattle for virus. Only mix with your own cattle once a clear result is known.
l Try to prevent nose-to-nose contact with neighbouring cattle of unknown status. Double fencing with a 3-metre gap is costly but may be the only solution in some cases.
l Vaccinate. If BVD does enter your herd, only vaccination will prevent big losses.
l Monitor herd status by performing the ‘check test’ on all groups of calves once they reach 9–18 months.