Welsh Government

Parasite Management Project - Monthly Update - April 2019

Most farmers have now started monitoring faecal egg counts and have received advice regarding when to monitor FEC and how the data should be used.


Testing ewes around lambing -

For the sheep farmers involved there has been good discussion on treating ewes around lambing time and how FEC testing can help with that decision. For those who have been testing we have found some interesting variations and what that means as shown in the 4 data extracts below :-


James Powell, Dolygarn

These were all taken 3 weeks before lambing and planning to worm them at same time as 8 in 1 vaccine or set stocked to lambing fields. Decisions made following these results: 1) to not worm most ewes in the 3 low FEC results groups, 2) to worm 80% of the Fat Twins and 3) worm all of the thins and triplets. Follow up tests to be done post lambing to see if results have risen in the low groups.


Irwel Jones, Aberbranddu

The 15th March tests were just at the point of lambing where we expect the spring rise to be at its highest. All FEC results were very low which would be helped by ewes being in very good condition and good quality grass in front of them. The decision was made not to worm and the post lambing test on 23rd April showed the FECs stayed low and backed our decision not to treat. This is great news as these ewes haven’t been wormed at all in the last year.


David Lewis, Halghton Hall

David starts lambing in mid-February through March and the initial visit was done towards the end of lambing. All ewes had been wormed with Cydectin drench (Moxidectin 3ml) at turnout. The test done on one group that were turned out and drenched 4 to 5 weeks before had a positive FEC of 280 epg which we wouldn’t expect to see due to the long acting nature of Moxidectin. It was advised to test another group, which was done on 22nd April – this time around 19 days after treatment and again an unexpected high count was recorded. This raises concern over the efficacy of Moxidectin and needs to be investigated further. All farms will have the chance to do a more thorough investigation of wormer efficacy later on in the summer.


Nicola Drew, College Farm

The ewes at College farm were all wormed at turnout. These FEC results confirmed that the wormers were needed. But it was advised to not worm all the singles to leave a percentage of ewes untreated.


These results show the importance of FEC testing to determine the best treatment plans. During the spring, it’s easy to assume that one group and / or farm will be very much like another, and the above shows that isn’t the case.

As lambs on most farms are nearing 6 weeks of age and older, the focus from now on will be around the lambs and particularly, in the first instance, Nematodirus.For the 3 farms focussing on cattle, May will see the amount of tests increasing with youngstock grazing the spring grass.