Using FEC as a monitoring tool
Are roundworms the problem?
- Evidence-based treatment
- establish whether roundworms are the cause of diarrhoea and ill-thrift
- confirm the presence of adult roundworms
- Testing could save the time and costs of worming sheep if roundworms are not the problem
When to treat?
- Regular pooled egg counts ~2-4 weeks apart
- Frequent monitoring can provide an indication of which fields are more wormy
- Highlights the optimal time for treatment
- Can be useful to improve flock productivity
- Correct timing = greatest benefit from wormer treatments
Which animals to treat?
- Targeting individual animals or groups
- Treating only those animals which need reduces excess chemical usage and costs
Did the treatment work?
- Only viable test to check if anthelmintic treatments are working
- Avoid wasting money & labor on treatments which are ineffective
- Wormer resistance is common – understand what works on your farm to treat effectively
Pooled or individual FEC
What egg counts CAN'T tell you...
- Eggs may not be present in the faeces before clinical disease – for example Nematodirus where the immature worms cause the greatest disease
- Other tools (e.g. weightgain) are better suited to monitoring productivity
- A single faecal egg count only provides a snapshot of what is happening…frequent testing is required to maximize benefit
- Egg counts can’t tell you which types of worms are present. Some species produce more eggs per adult worm (e.g. Haemonchus; barber’s pole worm) which can complicate interpretation of results
- Egg count results do not always reflect the number of adult worms in the sheep.
- Different types of worms producing different numbers of eggs
- Sheep’s immunity can impact the number of eggs in faeces and production impact e.g. around lambing in ewes (peri-parturient relaxation of immunity)
- High egg counts don’t always mean low productivity. Some animals can maintain production despite harboring worms (resilience)