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Victoria worms, flies and lice update - January 2015

Hamilton: Andrew Whale, Livestock Logic (

Livestock Logic Key Recommendation for February

  • After recent rainfall, you will need to monitor weaners around the 10th Feb to see if worm levels are on the rise.

Recent rainfall and a fortnight of mild overcast weather in South West Victoria have been most welcome after one of the driest springs on record. Hamilton airport has had 60mm for January, with bigger falls around the district. This rain is most welcome as dry feed in paddocks was quickly running low and pasture digestibility levels had been surprisingly poor considering the lack of spring rainfall. This green feed will greatly increase quality of pasture intake, both energy and protein levels, thus improving stock health. The question is: will it be short lived?

The next month’s weather will have considerable impact on pasture worm levels. With another month of summer ahead we would expect some hot and dry weather to kill worms (larvae) that are likely to be hatching on pasture now as a result of the summer rain and cooler weather. If this happens it will further help to reduce the worm population that we take into the autumn. If the current weather (cool days and dewy nights) conditions persist, then the worm life cycle will be able to complete and we would expect egg counts to start to rise in mid to late February in weaners and we could have a high pressure worm year in the district.

January worm levels have been low, as expected, after a very dry spring and lack of carry over feed, with a significant reduction in the numbers of sheep needing drenching compared to November and December of 2014 as shown below. 

For most this will mean (depending on weather conditions) that there is an opportunity to avoid a 2nd summer drench in many adults. As always, animals must be tested to have low worm egg counts, not assumed.

Fly pressure is not thought to become an issue in the area unless we see repeat rainfall events allowing fly numbers to build up considerably. The fly lifecycle takes 2 weeks and given previous dry weather it will take 2 to 3 generations (1 month of wet weather) for fly pressure to be an issue.  


Proportion of sheep needing drenching
Proportion of sheep needing drenching

Benalla: Tricia Veale (

In North Eastern Victoria it was very dry in December with only 25 mm of rainfall. Fortunately, so far in January we have received decent falls of 52 mm, but it is drying up again now.

There have been horrific fires, but at this stage most have fortunately been extinguished or are under control. The terrible fires locally have caused severe property and stock losses. Our thoughts are with those who have experienced this!

Many locals have supported these people by supplying fodder for those who have lost pastures and helping with replacing fencing.

The hard work and dedication of the Fire Services to our communities is truly wonderful!

Worm egg counts are generally low to moderate here, but farmers are still thoughtfully sending in tests to check out the situation, so that they don’t drench unless it is necessary.

Recent rain has caused flies to multiply and cases of fly strike are occurring.

Water in the dams has been lowering rapidly, but levels have recently slightly increased. If a green scum appears on any of the dams it is a good idea to get a water sample examined. Most algae are generally found to be harmless, but in some cases a bloom of toxic Blue-Green algae (BGA) may be present. Toxic blooms have already been reported this year on some dams in this area. Then arises the awful situation of telling the owner that the dam water is not suitable for stock use.

There are many types of algae that bloom. Most of them are harmless to stock, however there are 5 types of toxic BGAs.

The major pollutants that stimulate excessive algal growth are plant nutrients, nitrogen and phosphorus, which are contained in human sewerage, animal manures, fertilizers, detergents and also result from soil erosion.

If there is an algal bloom in the dam the first thing to do is stay out of the water and do not drink it (even if filtered and boiled). Then, keep stock away and provide an alternative water supply. Don’t spray water containing algal blooms on to pastures, crops, grapes, vegetables or fruit. Then get the algae identified. Only a microscopic examination in a laboratory will confirm the types of algae present.

Good wishes to all for and a happy, safe and prosperous 2015! 

For January 2015 state outlooks, please follow the links below:
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