What is faecal egg count?
The faecal worm egg count (FEC) is a method of examining the presence of gastrointestinal parasites in livestock manure. FEC is considered a quantitative estimation representing the exact number of eggs present per gram (epg) in feces. The quantitative result of this method gives the opportunity to make judgement on the livestock infection rate and to modify the response to treatment.
Why is FEC important?
Faecal egg counts are important because they can be used for.
- Identifying parasites that are resistant to specific dewormer drugs.
- Helping farmers in monitoring the pasture contamination rate of parasites.
- Selecting certain individual animals that have the genetic ability to resist parasites.
When deworming your livestock, it is important to remember to not only use the FEC method, but to combine this method with FAMACHA© card. The FAMACHA© card, illustrated by Figure 1, is a tool developed to aid farmers in the decision to deworm based on an estimation of the level of anemia present in you animal. Nevertheless, when the FEC score is high, and your animals exhibit no other clinical signs and symptoms of parasitism, deworming is advised
Monitoring FEC in can indicate whether parasite contamination of pastures is rising, helping farmers to determine when to move their livestock from one pasture to another.
How many samples are needed to have an accurate FEC?
To obtain a reliable result of parasites present in a group of animals, at least 10-15 samples are needed to estimate the groups average FEC.
Limitations of FEC
When presenting samples for FEC testing, it is important to remember that there are different methods used by laboratory technicians. The method that is used most frequently to carry out a FEC is the Modified Mc Master Technique.
Different species of strongyles cannot be identified as their eggs are identical to one another.
FEC are estimates, which means that there will be day to day variability in counts, because counting of eggs is influenced by the type of feed the animals eat, and dormant worms in the intestines of the animal do not lay eggs. Even though FEC has some limits, a high FEC indicates a high worm load, signifying a dewormer should be applied.
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