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Victoria worms, flies and lice update - July 2014

Hamilton: Andrew Whale, Livestock Logic (

Recent Results

Egg counts have been steadily rising over the last 4–6 weeks, a reflection of increased pasture contamination as the growing season progresses. There has been little incidence of mortality from worms as a result of substantial levels of feed on offer considering it is the middle of winter. This is providing stock with good nutrition, one of the best tools to fight off intestinal parasitism.

Despite this, we need to keep our finger on the pulse and continue to monitor all classes of stock regularly throughout winter, in particular weaners and lambing ewes, also keep in mind those dry sheep (wethers) that have been placed on the least feed and given little attention now that many are gearing up for lambing or lamb marking.

The following table represents sheep that have had counts greater than 200 epg from Livestock Logic Worm Laboratory in July up until 22nd July 2014

Class of Sheep

% Requiring Drenching

Mature Age Sheep


Maidens/Hoggets 2012 Drop


Weaners 2013 drop



Drenching Lambs not Weaned

Early lambing flocks will be getting close to potentially weaning lambs. A lamb's first drench often coincides with weaning, and, when weaning is delayed (which is rarely warranted), we often delay an important and required drench for lambs. Drench management of lambs from 8–20 weeks of age can play a big role in lamb growth rates, which we all want to maximise.

It is rare for lambs to benefit from a drench when younger than 8 weeks of age, but production effects often occur from 12+ weeks of age. For those hitting the sucker market it is important to consider a drench at 10–12 weeks of age (keep in mind withholding periods). The age that the first drench will be required varies with pasture contamination (ewe worm burden and paddock grazing history) and the level of feed on offer.

The best approach will vary with every property, but for those that have lambs from 6­–16 weeks of age, consider the best approach to minimising production effects on worms. Talk to your local advisor to ensure lambs are not held back by worms this spring.


Benalla: Tricia Veale (

Most parts of North Eastern Victoria and southern NSW have now received good rain.

In this area of North Eastern Victoria we have had 41 mm so far this month. The total for July was 97 mm. Local farmers are happy as this has filled the dams and helped grasses to grow, however, there are problems now with animals, trucks and tractors getting bogged/waterlogged.

Increasing numbers of farmers are now testing first to see if drenching is really needed. With ongoing difficult conditions this saves the expense of drenching unnecessarily and animals being exposed to chemicals that they don’t need, which also increases the likelihood of the development of drench resistance

There are still, however, many farmers that don’t test first! They often say that they know whether animals need drenching by looking at them.

Liver fluke, Fasciola hepatica, have been cycling on those properties where they are present. Recently quite a few ‘flukey’ properties have had positive test results.

Now with all the rain, it’s important to be aware that worm egg counts in sheep, goats and young cattle will likely be steadily increasing, especially the brown stomach worm, Ostertagia spp. Suggest that you test your animals to see what the situation is as some local properties have lost young lambs.

To be sure which species of worms are active on your property when you get a worm egg count done; ask for the eggs to be hatched out to determine their type… a Larval Culture.

It's also a good idea to test lambs at marking time.

For July 2014 state outlooks, please follow the links below:
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