23 April 2021


“At first sight this seems worrying but, because the testing is relatively sensitive and accurate, it means that on many farms we are identifying resistance in the early stages,’’ says sheep specialist James Hadwin, who is delivering the service for Farming Connect.

“That’s great news for the farmers involved because it means if they are careful and take advice, they can maintain good levels of worm control.’’

The initiative, which is funded through the Farming Connect Advisory Service, uses a flock faecal egg count Reduction Test (FECRT) to establish whether resistance exists to anthelmintic drenches.

In 2020, 49 sheep farms used the service, with testing carried out between June and November.

This was fully funded because the farm businesses worked in groups of between three and eight – it is 80% funded for farmers who want a one-to-one service.

Sampling packs were provided by parasite Management Company Techion and Faecal Egg Counts (FECs) were carried out on pooled dung samples - readings of around 500 eggs per gram (EPG) were needed to start the process.

FECs were taken from at least 90 lambs that had not been wormed for at least four weeks. 

Once this baseline was set lambs were split into four treatment groups with 20 in each group.

They were dosed under strict protocols with either a white drench (benzimidazole), yellow drench (levamisole), clear drench (3ML) or moxidectin.

A sample was taken from each lamb by a trained Techion technician – this was repeated at between 7 and 14 days later, depending on the type of drench used.

The samples were then sent to the Techion lab to assess the efficacy of that wormer group. 

Mr Hadwin, of JH Agri Consultancy (AgriPlan Cymru), says the results are concerning, but if the farmers take positive action to reduce their reliance on wormers on the back of their results, then they can achieve good worm control.

Actions include more attention to detail in flock management to reduce worm burden and also, should the stock need worming, in wormer choice. 

“The results in 2020 have shown that there is an issue with wormer resistance in the industry and that we need to act now,” says Mr Hadwin. 

“Hopefully this project is helping farms to get a handle on their situation and is encouraging people to follow SCOPS principles.’’

He hopes it will be a prerequisite to farmers working more closely with their vets and animal health advisors in formulating a robust flock health plan.

Overuse of wormers in the past has not only led to resistance developing but had added to cost of production, says Mr Hadwin.

“Time and labour are among the highest costs on sheep farms. If you don’t need to be drenching lambs, why do it?’’

When time is limited, lambs are sometimes dosed simply because they had been gathered for another management task, he adds.

“There is an element of ‘if the sheep are in for other things we might as well worm them’,’’ says Mr Hadwin.

“By planning ahead, and carrying out a FEC before handling, we know if the lambs actually needed worming. 

A main element of the Farming Connect project is to support farmers identify resistance and to put strategies in place to maintain wormer efficacy where possible, while also improving worm control. 

Each participating farm will receive a detailed report including their results and a set of recommendations along with an action plan outlining a way forward. Farmers are also encouraged to work with their vet or animal health advisors.

“Whilst there has been progress, there is evidence that some farmers are not working closely enough with their vet or animal health advisor to understanding why they are using a specific product,’’ says Mr Hadwin.

“A team approach to this issue is always best; we need to protect the wormers we have available and especially protect the new wormer groups by using them strategically.’’ 

Flock management advice is also given, to help to reduce the need to worm but whilst maintaining performance. 

“I would encourage Welsh sheep farmers to make the most of the help available under this funding to address what is a concerning trend within the industry and to take steps now to reduce the chance of resistance to wormers developing on their farm,’’ says Mr Hadwin.


A FECRT is a comprehensive test for detecting anthelmintic resistance. 

It is much more detailed and robust than a simple post treatment pooled test.

Instead of just showing treatment efficacy, the results give a much truer picture of resistance status at the time of testing.


Farmers who work within groups of between 3 and 8 farms will get this work done at no cost as the full cost - worth over £1,348.54 of testing and advice - is covered by Farming Connect.

Those who prefer to work on a one-to-one basis can get the same package of advice if they contribute 20% of the cost.

To apply for funding, contact your local Farming Connect development officer or the Farming Connect Service Centre on 08456 000 813. 

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