Whether there have been previous resistance issues on the farm or not, this testing is a worthwhile investment.
This is the only way to know if the drenches that you are using are actually effective on your farm. Parasite resistance to drenches is a continual problem, and once resistance to a drench has developed, drenches in that family will no longer be effective. This means that, not only are you wasting your money on buying a drench that does not work on your farm, but you will also have lower growth rates and a higher incidence of disease in your animals.
This test should be done between January and April, when the greatest number of the majority of worm species are present.
First, we need to make sure that enough worm eggs are present to start the test. A quick faecal egg count of 10 individual lamb faeces in a pooled sample (from lambs that have not been drenched in the past month) is carried out. You can drop this sample in to us.
On the day of the FECRT we need 10 to 12 weaned lambs per drench family to be tested, plus a few extras. A faecal sample from each lamb is collected and the lambs must be marked. Lambs then need to be weighed accurately and drenched with their allocated test drench before being released.
These samples are then sent to the lab for a pooled faecal culture of each group, and this tells us which parasite species are on your farm.
We re-sample each lamb from each group 7 to 10 days later, and these individual samples are run at the lab. Larval cultures are performed on any positive results.
The culture results tell us which parasites were present before drenching, and then how many of those parasites are there after drenching. This tells us which types of worms are resistant to what drench actives, and therefore what drenches are actually going to be effective on your farm.
The choice of drenches to test depends on the farm situation and drench history. Suggestions for group dosing are:
FECRT are an investment for the sustainability of your farm. A FECRT should be performed every three to five years. We can organise the FECRT for you and help with preparation and sample taking.