This strategy describes when to use strategic drenches and how to decide when tactical/therapeutic drenches are needed.
For those who like to see all the information and simply read through it in order. Each heading is a link to a page of information—the dot point provides a summary of the page.
Tip: Keep this page open and open the links in new tabs.
South Australian Winter Rainfall: When to test and when to drench
The times for routine worm testing and drenching in this region. Not all testing or drenching is routine; other times to do these are recommended by the Drench Decision Guide, according to details you provide about your mob of sheep.
South Australian Winter Rainfall: Drench Decision Guide
This tool recommends whether a mob should be drenched, the length of protection warranted and when to worm test again. It is your day-to-day tool on drenching decisions that should be used in conjunction with the annual program of routine testing and drenching times.
The DDG tool steers you through a series of questions about your sheep; choose the answer that applies to your mob (or make up your own scenario).
For those who prefer a problem based approach to learning, answer the following questions.
Each of the questions below links further down the page to the answers.
You can also click on each question below to go to WormBoss pages with related information.
1. What is the purpose of a strategic drench?
Strategic drench: a drench given at a critical time to sheep that are susceptible to worm infection (e.g. weaners and pre-lambing ewes) and also given at times to reduce worm larval contamination of a pasture grazed by the drenched sheep over the following weeks or months. The sheep themselves may have had a low worm egg count at the time of this pre-emptive treatment.
Note: Long-acting drenches are rarely required in South Australia. Unless professionally advised, use an effective short-acting drench when treating for worms. Where treatment for barber’s pole worm is also required, broad spectrum drenches are generally effective as drench resistance in barber’s pole worm is as yet uncommon in South Australia. However, this may be changing in areas where sheep have been introduced from interstate, locations where barber’s pole worm is more common.
4. The online Drench Decision Guide (DDG) for South Australia assists you to decide whether a mob of sheep should be drenched now and when to test again. Open the DDG and answer the questions it offers based on the scenario (from below) that you are using. Try at least three of the following scenarios.
Links to the learning topics for South Australian Winter Rainfall