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Victoria worms, flies and lice update - August 2017

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

Livestock Logic advises that:

  • worms are now at moderate levels in the south west
  • Spring is the time when stock performance should be good due to good nutrition but it can be compromised by sub-clinical worm burdens across all ages of stock

Livestock Logic Recommends that:

  • to maximise stock performance use egg counts to ensure target weight gains are achieved
  • the frequency of monitoring should be reduced to 3 weeks for weaners and 4–5 weeks for mature stock

The last few weeks in August have brought some more typical south west winter conditions with some good rainfall and some wind. It was mostly welcome rain as having a full moisture profile heading into spring gives producers great confidence. Early reports from lamb marking are that most producers are up 10-15% on last year mostly due to the awesome autumn break and kind weather in June and July.

September is still too early for flies to be a problem in our region, but we are getting asked plenty of questions regarding lice. 

Lice, always a difficult issue. If you have a new burden of lice it has likely come from sheep purchases and/or stray sheep, and it is likely that that same route of infection will occur again on your property this season. So biosecurity measures are the first thing that should be questioned if you are continually seeing lice on your sheep.

(Editor's note: If you had lice at last shearing and again this shearing, treatment failure is likely and you should review your treatment protocols. If you have used an SP or IGR lice treatment product, change to one of the other types where pesticide resistance has not yet been reported. You may like to read Bill Johnson's report for this month, covering lice. )

We continue to see the benefits of good nutrition this year because even though worm levels (egg counts) have been relatively consistent with other years (see below) we have not seen the mortality events typically seen over winter. However, those mobs that have not been monitored will have had reduced production.


In summary, spring is when farms need to have healthy and relatively worm free stock to maximise meat production. Visual guides are not great to make decisions on sheep worm levels, so utilise science/worm egg counts to determine stock drenching needs over the next few months.

The frequency of monitoring can be reduced to 3 weeks for weaners and 4–5 weeks for mature stock but doing egg counts is critical in terms of making money on farms.

Ensure you turn grass into product this spring with regular monitoring of all stock, weight gain now for ewes will be seen as increased condition score, and more lambs will be weaned in 12 months time.