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Australia's resource for control of worms, flies and lice in sheep,
and worms in goats

From the Editor

While a series of summer storms have prompted warnings of parasite (barber’s pole, flies and lice) outbreaks over the Christmas period, much of the grazing regions across the country remain parched. Nonetheless, November is the time to implement control strategies to protect young stock from parasitic infections over the summer period and into autumn.

In good times, when parasite burdens are high, drenches for young stock need to be very effective with all at-risk sheep drenched. In dry times it is critically important that decisions about drench choice and which sheep need to be treated, are based on an understanding of refugia.

Contributors to this month’s state outlooks reflect that overzealous use of drenches in dry conditions, while often necessary to prevent productivity losses in stock on a poor plane of nutrition, markedly increases the level of drench-resistant worms, a major cause of drench failure.

Consider, based on worm egg counts where necessary, whether the whole mob needs to be drenched or just some of the mob or just some mobs on the property. Leaving some classes of sheep undrenched will promote refugia and help save drenches (read WA and VIC state outlooks).

This month's feature articles describe why drench resistance or failure of drugs to kill worms, is a major problem to sheep producers and provide answers to the difficult question, “What works for prime lambs on irrigated pastures in Tasmania”.

Keep these practices in mind:

1. WormTest

2. Drench Test

3. Use the Drench Decision Guide for your region.

Scary statistic: It has been reported that up to 40 per cent of producers observe signs of lice in their flock each year.

We know that integral to lice control is neighbours working together to secure border fences. Here is one such story of neighbours developing an action plan to work together to control lice.

Maxine Murphy

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Feature articles

Worm control under irrigation in Tasmania

by Paul Nilon, Nilon Farm Health, Tasmania

Irrigation is frequently used to provide high quality summer and autumn forage for finishing lambs. While there is a dearth of good trial work to know what works and what does not with regards worm control on irrigated pastures, there are suggestions from experience and first principles. >> Read more.

Drench resistance—a big cost that flies under the radar

by Brown Besier, DAFWA

Drench resistance is a major problem to sheep producers for two main reasons: it is costly, and it’s mostly invisible. >> Read more.

Getting the most from your fly treatment

by Deb Maxwell, ParaBoss Operations Manager

Timing of animal husbandry practices and treatments have a major impact on the flystrike risk, but weighing up the impact from each and the best time to do them can be a daunting task. However, FlyBoss Tools make the job fast and easy. >> Read more.

Genes, not lice

from the LiceBoss web site

Plan only to bring home the good genes with your ram purchase. No matter how much you trust your stud, good biosecurity assumes incoming sheep carry lice.  Now is a good time to review your introduction and quarantine policies. >> Read more.

The quick quiz

This 3-question quick quiz tests your knowledge of sheep parasites and their control. 
>> Take the quiz.


State Outlooks for November 2015

New South Wales
>> full report

A barber’s pole alert for the tablelands and plains has been advised due to the recent rain and warm weather. Flies and lice are also active and there are reports of Eperythrozoon (M. ovis) infection.

>> full report

South west Victoria remains dry with plenty of lambs now going onto full grain rations for finishing. Read the warnings about drenching during dry weather!

>> full report

Longreach Pastoral College has actioned its internal/external parasite control program as rain has brought out the flies and worms. In the south, significant rainfalls have producers thinking about restocking and prompted advisors to emphasise the need for increased monitoring activity for worm and fly.

Western Australia
>> full report

Time to decide on a strategic summer drench for lambs, weaners and hoggets. Drench onto stubbles if available and leave some adult sheep undrenched.

>> full report

Very dry in the midlands. There will be little benefit in a second summer drench if conditions remain dry. Indeed, drenching when it is so parched and bare only promotes resistance in worms leading to drench failure.

South Australia
>> full report

Report not available at time of publishing.