A new test to screen herds for liver fluke has been developed, which could help to reduce the risk of cattle developing immunity to existing de-worming treatments.

Cattle become infected with liver fluke by eating grass contaminated with cysts containing fluke eggs, shed from mud snails found in damp, marshy areas of pasture.

Infection is very common and even low levels can lead to serious losses in production. It can extend time to slaughter and reduce milk yield by up to 15%.

The wet weather during late summer is likely to increase the risk of liver fluke infection for cattle on many farms this year.

The test involves the collection of faecal samples from a number of cattle in the herd which is then analysed by a lab and a single count reported.

The new method was created as part of a joint project involving AHDB and led by the University of Liverpool with the Moredun Research Institute.

Mary Vickers, AHDB Beef and Lamb senior scientist, said controlling liver fluke is a 'difficult task', particularly because of emerging resistance to some of the flukicidal products used to treat cattle and sheep.

“Looking to the future, reliance on de-worming treatments alone is likely to be unsustainable so treatment informed by diagnosis is crucial for disease control.”

The new testing method known as ‘composite faecal egg counting’ is suitable for both dairy and beef cattle and allows herds to be screened for infection, with targeted treatment administered as required.

This composite test was found to be at least as good as other diagnostic methods, such as the copro-antigen ELISA, for identifying infected herds.

To save time testing in labs in the future, the project team is working to develop pen-side tests, which farmers and vets can use to give diagnostic results straight away, allowing immediate, targeted treatments.