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South Australia worms, flies and lice update - August 2019

SA WormBoss Worm Control Programs

SA WormBoss Drench Decision Guides





Adelaide: Colin Trengove, Sheep Health Lecturer (UA Roseworthy campus) (

Most of the State is faring well in the rainfall stakes but limiting in the upper north, Riverland and Mallee. The 3-month outlook is not encouraging, but we can only hope the Westerlies throw up some unpredictable surprises.

Worm egg counts have been uniformly modest in all but the south-east with ewes and lambs alike producing counts below the usual trigger point for drenching. In contrast, a third of counts from the south-east have indicated a need for drenching. It is hard to interpret these results without knowing the drenching and grazing management history, but at least appear encouraging. While conditions have been cold pasture growth has been reasonable, and so it can only be speculated that worm larval pick-up has been limited.

Lamb prices continue to climb in contrast to wool prices, and so the impetus is there to optimise their survival and performance. We can’t do much about the volatility in global trading, especially for wool, but we can control growth rate, health management and welfare in livestock. Pain management is now a standard welfare procedure at lamb marking, given the obvious positive responses to treatment with Tri-Solfen for mulesing wounds and Metacam or Buccalgesic for tailing and castration. “Numnuts” is also now an option to further reduce pain associated with the latter procedures. Speak to your veterinarian/animal health advisor if you are not familiar with these products.

In addition to the above procedures, worm egg count monitoring and vaccination are a couple of simple risk-management tools that are easily done and quite cost-effective to avert potential disease risks. Another is to check mineral status as deficiencies are most apparent in late winter/early spring—especially if lambs are grazing lush grass-based pastures. In contrast, providing buffers and mineral supplements are always good insurance for lambs receiving a grain-based diet.

Finally, consider the opportunity to do a drench trial in the lead up to weaning. Average pasture growth years are usually the best ones for checking which drenches are effective. This can be simply done by checking egg counts before and after drenching with one or more chemicals and enable the development of a drench use plan for the next 3 years.

For August 2019 state outlooks, please follow the links below:
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