8 May 2009
Sheep producers who have experienced more than 3% of ewes aborting this lambing season are being urged to take advantage of the subsidised blood testing service that detects exposure to toxoplasmosis and enzootic abortion (EAE).
FlockCheck, a subsidised diagnostic service from Intervet/Schering-Plough Animal Health, requires vets to take blood samples from 6-8 aborted ewes.
Data collected nationally shows that the most commonly diagnosed causes of abortion in sheep continue to be EAE and toxoplasmosis, despite the availability of cost-effective vaccines.
“In 2008 over 260 flocks took advantage of the subsidised FlockCheck service with 78% testing positive for toxoplasmosis and 40% positive for EAE,” points out Paul Williams MRCVS, Livestock Veterinary Adviser with Intervet/Schering-Plough Animal Health.
“The 2008 FlockCheck results are consistent with findings from previous years, in that around four out of every five tested flocks are infected with toxoplasmosis. Additionally, we also find consistently that about a third of flocks are harbouring both toxoplasmosis and EAE infections. Unfortunately, whilst EAE can cause abortion storms, many farmers may not realise they even have a problem, but there’s no doubt that these infections do erode flock profitability.”
Paul Williams explains that the costs of lowered productivity are so great that vaccination is a highly cost-effective route to disease control. “If toxoplasmosis is present in your flock, vaccination has been shown to produce a 6.4% increase in the number of lambs. The situation can be more complex with EAE if many ewes are already carriers of the disease. However, most farms will see a significant benefit from vaccination during the following season.
“Assuming ewes are vaccinated with both vaccines at the start of her productive life in the flock (which is normally five years), any 100 ewe flock only needs to deliver an additional 3.5 lambs or an increase of two productive ewes across the group to pay for the investment,” he says.
FlockCheck – and the abortion vaccines Enzovax and Toxovax – are available from veterinary surgeons.
