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Victoria worms, flies and lice update - October 2014

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

Summer drenching planning and strategy starts now.

Dry weather in the South West since August has given us a terrible spring with pasture growth rates well below normal levels. While rain now would be welcome and pastures are still green we are realisticly in drought conditions. Active farmers are already securing large quantities of supplementary feed and selling dry and non-breeding stock while prices are relatively good. Those that have done feed budgets and are aware of the costs and grain required to get them through to the autumn break will be better placed to handle a long summer

Egg counts, as you can see below, have reduced since September, but we are still recommending drenching of 35–40% of the mobs being tested. Weaned lambs should be the focus of Worm Egg Counts over the next month or so, as well as any mobs not tested for 4 weeks.

Egg counts in November are often neglected. Instead we wait til December to see if a ‘1st summer Drench’ is required. If egg counts are high in November then drenching should be undertaken immediately, if low then do not drench but re-test in December. If moderate then there is no need to re-test in December, just pencil in a drench for a month’s time. Delaying the drench improves its effectiveness, as larval pickup after early December this year will be minimal.


November adult sheep drenching trigger levels (guide only)


Benalla: Tricia Veale (triciav7@bigpond.com)

We have had a moderate amount of rain here in North Eastern Victoria with 60 mm for September, but only 10 mm so far for October. Dams are moderately full but the local area is superficially very dry. Farmers are concerned about crop survival as there has often been a frost in the early morning.

We recently visited a relative’s farm in South Australia. He had planted many hectares of wheat that had only grown to a very small height and were going brown due to lack of water. A very worrying situation!

Worm numbers are still at moderate to high levels in most areas. It’s a good idea to check this by getting worm egg counts done before drenching. Many farmers are now routinely testing their sheep, which helps to avoid unnecessary drenching. Due to the increasing evidence of drench resistance this is very important. Recent reports in the Weekly Times indicate that worm drench resistance is very common in cattle.

It’s important to be aware that the use of combination drenches in sheep reduces selection pressure against drenches. Cattle producers need to adopt these principles. Trifecta is a recently launched triple activity oral drench suitable for sheep and cattle.

If you are on a property where there is a history of Liver Fluke being present, suggest that you get this tested as they are still active on some local farms.

Bladder Worm (Cysticercus tenuicollis) is evident, the fluid filled cysts have been found in some sheep carcasses. Dogs can acquire this tapeworm by eating sheep offal that contains the cysts. These do not infect the dogs, they are only the carriers. Dogs pass tapeworm segments containing thousands of eggs onto the paddock, where the sheep consume them with the grass. So ensure that your dogs are not fed raw sheep meat. For more see http://www.wormboss.com.au/worms/tapeworms.php

Barber's Pole worm (Haemonchus contortus) is now active, and it is one of those worms that are not being identified early enough. The mature worms lay many thousands of eggs that allow numbers to build up very quickly. This worm lives in a sheep's stomach and sucks blood, causing anaemia and weight loss.

Problems have arisen on some local properties where sheep from dry areas have been introduced onto damp paddocks. They very soon pick up worms and the immature stages can be causing anaemia shortly before there are faecal egg counts.

A total worm count from the intestines of a dead animal will give an indication of the worm burden and the types present.