Best Practice Usage of Long-Acting Drenches

Usage of short-acting primer drenches at the same time as a longer acting product can greatly reduce resistance selection as the primer can remove the highly resistant adult worms that would otherwise have a long period of breeding advantage in the treated sheep whilst more sensitive worms are being excluded (for up to 100 days) .

Sheep treated with longer-acting products can be monitored after dosing to assess how much resistance selection is occurring. Such monitoring may indicate a need to administer an exit drench to remove surviving, resistant worms or at least give an indication on whether a primer dose is needed next time the same product is used².

Speak to your local Animal Production Specialist (APS) to learn more about this issue and how to implement best practice for the usage of longer-acting products.*

• Download the full technical flyer here
• View a list of our Animal Production Specialists (APSs) and Animal Health Advisors in sheep regions of Australia* here, and/or
• Find your local branch here

Animal Health Advisor, Nic Dawes, applying a drench to sheep.

_{*Any specialised advice provided to customers will be subject to terms and conditions. Nutrien's Animal Production Specialist advice is not a substitute for obtaining your own personalised veterinary advice for your circumstances.}

¹ https://wormboss.com.au/tests-tools/managing-drench-resistance-sheep

² https://paraboss.com.au/news/long-acting-worm-treatments-the-good-the-bad-and-the-ghastly/