Last summer, Totally Vets completed a number of Faecal Egg Count Reduction Tests (FECRTs) in order to examine drench resistance on our clients' properties. Sheep results are available elsewhere on the website.
There were only a small number of farms that tested calves, so this year's results have been combined with other farms surveyed in 2006. The results below are compared to the 2006 national drench resistance survey results.
Levamisole - clear drench
This is currently effective on all farms tested in this district, although nationally 6% of farms had Levamisole-resistant worms.
Benzimidazole - white drench
White drench worked well on one farm, but on most others both Ostertagia and Cooperia showed resistance. Seventy six percent of farms surveyed nationally had resistance, attributed mainly to Cooperia, but Ostertagia are commonly resistant to white drench in our area. This has implications for those using double combination drenches.
Ivermectin - endectocide
Cooperia are very commonly resistant to endectocide treatment. Ninety two percent of farms nationally have endectocide-resistant parasites.
Summary
Cooperia are commonly resistant to both white and endectocide drenches. Do you know the resistance status of Cooperia on your farm?
On farms where Ostertagia are resistant to white drench, the routine drench choice may be different from our standard recommendations. Do you know the resistance status of Ostertagia on your farm?
FECRTs provide vital information, meaning the money you spend on drench is not only killing the worms, but aiding optimal productivity on your property.
Our FECRT service will be available again this summer. If you are interested in the drench resistance status of the parasites on your farm, contact Greta Baynes at Totally Vets on 06 323 6161 or e-mail admin@totallyvets.co.nz and we will contact you nearer the time.
