What the heck is a FECRT?
A faecal egg count reduction test (FECRT) is a way to ensure that you are spending your money wisely. There is no doubt about the production response possible from drenching a parasitised animal with an effective anthelmintic. However, when working out the annual cost of your drench, wouldn't you like to know the money you spent was the most cost-effective way to get the productivity you desire?
We can help you with a FECRT, sometimes referred to as a drench test. Different types of drench (single actives and various combinations) are tested on each farm - the type and number of drenches will be determined after discussion about your historical drench use and evaluating the responses you have had.
The best time to perform this test is when most worm species are present within the animals, usually summer. A small number of faecal samples are tested initially to ensure the faecal egg count (FEC), which represents the parasite burden within the animal, is significant enough for the test to begin. A small mob of animals (weaned lambs or calves) are divided into groups and allocated to a specific drench. Samples for a FEC are taken at the time of drenching and 7-10 days later to determine how much the parasite burden has decreased.
The pre- and post-drench counts are compared to determine how much the FEC has reduced. That is how effective the drench was at killing the parasites present. The different drenches are compared with each other and a control group. In groups of animals where there was less than a 95% reduction in the parasite burden, the faeces are cultured so the eggs hatch and the resistant worms are identified.
Drench resistance is an increasingly important issue on farms. Primarily the issue arises from cost of drench, labour costs of drenching and the expected production response to offset these costs. Although the susceptible worms will be removed by the drench, worms resistant to the drench will continue to parasitise these animals and limit liveweight gains. The next issue is the shedding of eggs from resistant worms onto the pasture. If there are no susceptible eggs on the pasture (from leaving some of the mob un-drenched), there is no dilution occurring and only resistant parasites will be ingested. If the same drench is used again on these animals, it will have even less effect than before.
Knowing which drenches work effectively on each worm type on your property can be used to tailor a specific drench plan for your property including types of drenches to use, timing of drenching, class of stock to drench and alternative control methods (such as leaving some animals un-drenched). These recommendations are property-specific.
If you would like more information or would like to do a FECRT to ensure effective drench use on your farm, please speak to Greta at Totally Vets in Feilding.
