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Victoria worms, flies and lice update - August 2016

VIC WormBoss Worm Control Programs

VIC WormBoss Drench Decision Guides


Hamilton: Andrew Whale, Livestock Logic (a.whale@livestocklogic.com.au)

Livestock Logic Key Recommendations

  • Don’t let non-clinical worm burdens reduce your weight gains this spring. Animals can look good and put on weight, but less than they should, due to moderate worm burdens typical of spring.
  • Monitor
    • Weaners every 3 weeks throughout spring.
    • Adult stock every 4 weeks.

Lawn mowers are clicking into gear and pastures are starting to move in the south-west as the days are getting longer and warmer. Seasonal conditions look ideal with plenty of moisture around, and forecasts of a wet spring are most welcome for all livestock producers.

Stock health has mostly been good, with the exception again being the significant levels of hypocalcaemia in pre-lambing ewes, particularly in crossbred twin bearing ewes, and reasonably high levels of abortions in ewe lambs with Listeria being the most commonly diagnosed pathogen.

Egg counts have been very low throughout the winter, but are starting to rise now as pasture contamination levels start to become significant. The good news is that with pastures almost at the point of exceeding demand on many properties, there will be some dilution of worm eggs due to the high pasture levels in paddocks.  

It is still very important to monitor all stock throughout the spring, but at a reduced frequency compared to that in the middle of winter. We would suggest monitoring weaners every 3 weeks and adult stock every 4–5 weeks from now until pastures hay off.  

Weight gains for the next 3 months should be in the order of 150–250 grams per day for most stock. A non-clinical worm burden (no dramatic scours, weakness or deaths of sheep) could reduce the growth rates by 30%, or 70 grams/day for 100 days, which is 7kg, the equivalent of a condition score in 50 kg ewes. Most will be aware of the implications this has on reducing conception rates in the next year (20–40% reduction depending on genetics).  

In terms of reduced grain requirements, a reduction of the order of 30 kg ($6/ewe) of grain per head will occur due to reduced supplementary feeding due to better growth rates in sheep over the spring.   


Figure 1: Percentage of Mixed Age Ewes and Weaners requiring drenching from Livestock Logic Laboratory from March-August this year.

Message: Ensure stock reach their target weights this spring by egg counting weaners mobs every 3 weeks and adult stock every 4-5 weeks until pastures hay off, to ensure that worms don’t reduce the kg of meat that could be produced on your farm this spring.