Taking dung samples from lambs for a faecal egg count (FEC) does not have to be a time-consuming task for sheep farmers, Matt Colston from animal health company Elanco told an online event hosted by the National Sheep Association last Wednesday.

During his presentation, Colston urged farmers to approach parasite control by routinely monitoring FECs, instead of periodically dosing lambs based on calendar dates.

This allows lambs that have worm burdens which are impacting daily weight gains, but are not yet causing visible signs of scour, to be identified and treated early.

Collecting samples for a FEC does not have to be an extra job

If lambs do not require treatments, an evidence-based approach using FEC means money is not spent unnecessarily on dosing, and worms will not be selected for anthelmintic resistance.

“Collecting samples for a FEC does not have to be an extra job. It can easily fit into the normal shepherding day,” Colston maintained.

“You can do it when you are routinely checking sheep. Wait for a lamb to get up, stretch and dung, then move over and take a sample of it,” he said.

Faeces for an FEC must be fresh, so stale dung laying on pasture should not be sampled. Dung from 10 to 15 lambs should be used in one pooled sample to make it representative of the group.

Other ways to take fresh dung samples include holding sheep in the corner of a field, or after lambs have passed through a clean yard or laneway.

FEC can be taken once lambs are three to four weeks old, and should be repeated every two or three weeks during the summer.

When dosing is required, do a post-treatment FEC check to see if the treatment has worked

Giving samples to a vet who then sends them to a laboratory is generally not recommended as the results turnaround can be too slow.

Instead, send samples to a vet who checks FEC in their own practice and will be able to give you results within 24 hours. Vets in NI typically charge around £15 per sample for a FEC of roundworms.

“When dosing is required, do a post-treatment FEC check to see if the treatment has worked. This should be seven days after using group two (yellow) wormers, and 14 days for all other compounds,” Colston said.

The veterinary consultant also urged sheep farmers to make more use of group four (orange) and group five (purple) wormers.

Sheep can be held in the corner of field and samples taken as lambs dung.

The advice has been to use the likes of Zolvix or Startect as a quarantine treatment for newly purchased sheep as these products typically have no issues with resistance. This prevents newly bought-in sheep from bringing in worms that are resistant to other anthelmintic groups.

Late-season treatment

More recently, it has been recommended to use an orange or purple wormer as a late-season treatment in lambs to remove any resistant worms that have built up over the summer.

However, there has been limited uptake of this approach among farmers, mainly due to the higher price of group four and five products.

“They should really be included in a worm control plan for all farms now, before there is an obvious failure of the other three groups,” Colston maintained.