Making the Most of Faecal (Worm) Egg Counts (FEC) on Farms

• A Faecal Egg Count (FEC) measures the number of worm eggs in faeces (dung) and is used to monitor the worm burden in sheep.
• The results are presented as the number of eggs per gram (epg) of faeces.
• The number of eggs per gram is an indication of how many adult egg laying worms are in the gut of the sheep.

The diagram below shows the general life-­cycle of roundworms in sheep:

How can we use FECS?

• To help determine the need to treat a group of sheep – see below
• Test if a treatment has been fully effective
• Give us information on the amount of contamination going onto the pasture. If FECs are used regularly, you can build up a picture of what is happening on the grazing. This greatly enhances the accuracy of decisions to treat and also when to change pasture to avoid a high challenge.

How can I get FECs done?

Faecal Egg Count (FEC) testing kits are available from Murray Farmcare, these can be either collected in-store or delivered on farm. For more information, please contact your territory manager. Additionally, we will soon be able to carry out testing in-store at the pharmacy counter in our Dumfries store.

Ideally, FECs should be carried out regularly (2-­4 weekly) through the grazing season. Interpretation of an FEC result is quite complex and depends on a number of factors which you should discuss with your Vet or adviser. The figures below apply to pooled samples and are ONLY A GUIDE where Haemonchus contortus is not present.

Taking Faecal Samples -­ to obtain a reliable result from a FEC there are 5 golden rules::

• Fresh dung is essential, ideally less than 1 hour old (if it’s warm to the touch it is fresh!) Always wear gloves and wash your hands afterwards. Take at least 10 individual samples per group. For larger groups 10% is ideal.
• If you are combining individual samples to send a pooled sample (or using a DIY system), then each individual sample MUST BE THE SAME SIZE for the result to be representative. Laboratories normally ask for individual samples and will take equal amounts from each in the lab.
• Sheep should be healthy and have had full access to pasture and/or feed before sampling, otherwise the FEC will be difficult to interpret.
• Samples taken must be completely random. Do not pick and choose which faeces to sample. Use pots provided (fill to the brim) or airtight bags. Make sure you don’t mix ewe and lamb samples when testing unweaned lambs.
• Make sure the air is expelled from the bag and keep the sample cool (preferably hygienically in a fridge) and get it to the practice or lab within 48 hours – we don’t want eggs hatching or the result will be unreliable. Don’t post on a Friday!