What is refugia?
Refugia is a population of worms that are not exposed to drench.
Having some worms present that are not exposed to drench helps to dilute the gene pool of resistant worms with susceptible worms – this aids in slowing the build-up of resistant worm populations, so our drenches continue to work better for longer.
Video: Beef + Lamb New Zealand
Ideas to help create refugia:
- Have a minimum 28-day drench interval
- Run a handful of older un-drenched animals with younger animals that are being regularly drenched. (i.e some MA ewes with lambs)
- Do not drench and shift to “clean” pasture
- Leave a proportion of older or better condition animals in a mob un-drenched
- Avoid grazing solely young animals that are regularly drenched in one area only
