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Victoria worms, flies and lice update - December 2020

VIC WormBoss Worm Control Programs

VIC WormBoss Drench Decision Guides





Queensland worms, flies and lice update - December 2020

Hamilton: Lexie Leonard, Livestock Logic (

Key Recommendations

  • Worm egg count (WEC) monitoring of weaners is imperative every four weeks over summer
  • Rams should get an effective drench 6–8 weeks prior joining
  • Ensure if you are buying stock in you have a biosecurity plan set up to prevent the introduction of resistant worms or lice

The end of the year is fast approaching, pastures are starting to dry off and sheep poo is starting to harden up — which mean it’s time to fire up the feeding charts and start having a good look at your stock to time your ‘summer’ drench. This year with the long spring conditions, many mobs of sheep haven’t required drenching post mid-spring and the traditional timing of a ‘first summer drench’ of late November–early December has gone out the window. We anticipate late December to be the time most mobs in the district will be needing a drench based on WEC results and the condition of pastures. Now is a good reminder to feed test your pastures if relying on them for ewe nutrition — there have already been several pasture tests from around Hamilton coming back will low digestibility, and not enough nutrition to maintain adult ewes. This could be a year many producers are caught out at joining time with feed that looks adequate now but definitely isn’t!

A lot of standing feed across the district, and continuing small showers will keep worm larvae pretty happy and thriving on pastures well into summer. This year with a La Niña we can’t rely on environmental decontamination to remove the majority of worms from pastures (unless you have large amounts of cattle to remove the standing feed!). Well-timed drenches will help keep paddock contamination under control, but keep in mind regular monitoring will still need to be done over January and February, as there will likely be worm pick up from pastures over summer. Adult cattle that are in good body condition would likely not benefit from drenching, but should be drench with a mectin oral or injectable towards to the end of summer to remove any potential encysted stomach worms.

Both sheep and cattle weaners should have been given a drench at weaning time, followed up with regular 4–5 weekly monitoring. WEC monitoring of calves still on mum can give a good indication of pasture contamination, so don’t discount monitoring calves that haven’t been weaned yet.

Flies have been causing sporadic issues around the southwest region for the past few weeks. We expect flies to become more of an issue heading into summer, especially for sheep grazing tall feed. Fly prevention now will help keep total fly numbers low on your property. There have been some discussion around potential resistance developing to certain chemicals, so keep a close eye on your sheep after any chemical application. Any concern about resistance should be reported to the chemical company ASAP so it can be followed up.

Lice remains a constant thorn in producers’ sides, there have been plenty of reports this year of lice causing issues. As with all parasite management, starting with a solid management or eradication plan will ensure success; an ad hoc approach always ends in frustration and continued issues. Having a lice treatment plan as part of your general biosecurity plan is a great place to start to ensure lice aren’t inadvertently brought onto your property. Composite lambs coming through fences is a whole other issue altogether!

Merry Christmas to all our clients, we hope you get a well-deserved break over Christmas!

For December 2020 state outlooks, please follow the links below:
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