An updated Blowfly Watch service to provide sheep farmers with up-to-date information on the blowfly risk in their area has been launched by Elanco in partnership with the National Animal Disease Information Service (NADIS).

Elanco ruminant technical consultant Matthew Colston, Elanco says this new service will help sheep farmers take a preventative approach to blowfly strike control.

“With mortalities due to blowfly strike costing farmers £209 per lamb and £184 per breeding ewe, preventing cases should be a key priority for sheep farmers,” he says.

“The new Blowfly Watch service works by looking at different risk factors, like soil temperature and humidity, giving farmers accurate information on the number of flies in their area, which can then be used to plan in preventative treatment.”

The Scottish Farmer: Elanco's Matthew Colston emphasises the preventative approach enabled by this service.Elanco's Matthew Colston emphasises the preventative approach enabled by this service.

By splitting the country into 40km squares, the service will send farmers alerts when the risk of blowfly changes in their local area.

It has been demonstrated that preventative treatment of both ewes and lambs is the most cost-effective strategy against blowfly strike.

“Changing weather patterns have meant the blowfly season can start as early as March and last beyond September, meaning farmers can’t just plan based on previous years, especially in northern parts of the country,” explains Mr Colston.

He explains the irritation caused by blowfly maggots inside the fleece and skin prevents the sheep from grazing, while secondary infections can lead to death by septicaemia.

“Blowfly strike can happen very quickly, with 94% of farmers reported to have been caught out by it,” says Mr Colston.

“However, by signing up to the Blowfly Watch alerts, farmers will have the heads-up on when to apply a preventive treatment, before cases occur,” says Mr Colston.

Once the risk of blowflies has been identified, Mr Colston recommends protecting sheep with an Insect Growth Regulator (IGR), such as those in the CLiK™ range.

The range can provide between eight to 19 weeks’ protection, depending on the product, with CLiKZIN™ offering a meat withdrawal period of just seven days.

Mr Colston says IGR products must be applied in the right amounts, and in the right way, to get the best results.

“I’d advise using the four-stroke application method to ensure there’s a four-inch bandwidth of product applied to the animal. Take extra care when lambs are small, because a smaller target requires greater precision.”

If flocks are affected by blowfly strike, they can report the case to the Elanco Blowfly Tracker so that other farmers in their area know about the risk.

Sign up for Blowfly Watch here