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ParaBoss News - April 2019

Don't lose the flystrike chemicals that work for you
Don't lose the flystrike chemicals that work for you
Look for WEC ASBVs when buying rams.
Look for WEC ASBVs when buying rams.
Fly larvae become pupae (darker) that burrow into the ground
Fly larvae become pupae (darker) that burrow into the ground
Plunge dips are a good choice to eradicate lice
Plunge dips are a good choice to eradicate lice
Goat lice! Source: NC State Extension
Goat lice! Source: NC State Extension


Fast Fact: Sharing the love

In far-flung places like Africa, humans and livestock can share infection by any number of protozoal diseases. However, worldwide, the number of “worms” that people and sheep share is relatively limited. Liver fluke (Fasciola spp) is the one many people know about; people contract it if they eat water plants (most notably watercress) harvested from infected environments.

A rarer example is gullet worm (Gongylonema spp), which causes harmless nodules in the rumen and oesophagus of sheep, but can result in painful swelling in the oral mucosa of humans. Mind you, to contract it you have to ingest the coprophilic beetles that are the intermediate host.

The final example is the sheep nasal bot (Oestrus ovis). An insect, not a worm; the mature adult squirts larval-laden juice close to the nasal passages and the little buggers migrate up the nose and frontal sinuses to mature. So if your best friend suddenly starts snorting and running mucus don’t jump to conclusions about lines of white powder, they may have nasal bot. 

Feature articles

You can slow down resistance development in flies

Introduction by AWI Sheep blowfly resistance management strategy working group

Lucilia cuprina, the Australian sheep blowfly, initiates most cases of flystrike on Australian sheep. Like all insect pests, it has the potential to develop resistance to insecticide treatments. Some Australian sheep producers have reported shorter protection periods than claimed on the label of the flystrike products they have used.

On investigation, some of these cases are the result of improper application or heavy rain following insecticide application, however in a number of cases the presence of resistance has been confirmed.

This is a timely reminder for sheep producers to implement resistance management strategies to maintain flystrike protection for their flocks and slow the development of resistance within their local fly populations. >> Read more.

ASBVs are the way to go!

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

Last month we talked about ASBVs for flystrike: dag, wrinkle and breech cover. On the same theme, ASBVs for worm resistance should be standard fare in all ram sale catalogues. ASBVs are more potent than stand-alone WECs because they incorporate pedigree information into the calculations. This page gives a great explanation of ASBVs and why they are more potent than raw WEC, and here you can see the methodology. The validity of ASBVs as a measure of resistance is explained. >> Read more

Where do they go if there is no active strike?

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

Strike flies, like worms, have an off-sheep phase. Lucilia cuprina (the common sheep blowfly) spend the winter as larvae or pre-pupae in the ground. So what? Well, you may extend the safe period in the spring if you trap early emerging flies (a bit like strategic drenching, but without the risk of resistance). A client with excessively skinned sheep was want to nail the little yellow LuciTraps to posts. I suggested he nail a few of his weaners instead; he did not share my sense of humour. Notwithstanding, the (potential) benefits of fly trapping are explained here and LuciTraps are still available from this supplier>> Read more

Why take the plunge?

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

Maybe a coincidence, but two clients rang in the last few weeks wanting to plunge dip. If you have a working plunge dip, it is in all likelihood, the most reliable way to eradicate lice. If you do not have a plunge dip there are some very professional operators providing an immersion dipping service. Plunge and immersion dips need to be operated well to keep chemical at the right concentration. This is explained here. Immersion dip operators will understand all this, so sheep owners may just want to choose the best chemical for their situation. The choice is not huge.

Try out the Lice and Flystrike Products Tool: select “lice” and “short wool dip for lice” from the drop-down menus to see the lot. It’s suggested you avoid diflubenzuron (an IGR) and synthetic pyrethroids because of widespread resistance. Organic producers can use magnesium fluorosilicate on a restricted basis, but there is no mention of rotenone (the other component in Flockmaster) in the ACO standards, so dipping may not be possible. Flockmaster is approved for use by biodynamic farmers. Finally, as we move into the cooler weather (at least on the Tablelands and in Tasmania) be mindful of exposure and choose your dipping day carefully. >> Read more

Goat Lice? Think differently!

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

In Australia, there are 4 species of lice found on goats: 2 sucking lice and 2 biting (or chewing) lice. Sucking lice (Lignonathus spp) can cause serious health issues, particularly in kids. This is in contrast to sheep, where sucking lice (face and leg lice) are a bit of a novelty and present a “Holy !*# moment", as in "Holy !*#, my sheep have lice!”). Credible local information on goat lice is scarce, but this link contains most of the basics (scroll down to page 8). There are 3 types of products on the database: one SP backline, one rotenone dust and a couple of Diazinon (OP) spray products. >> Read more


For April 2019 state outlooks, please follow the links below:

New South Wales
Victoria
Queensland
Western Australia
Tasmania
South Australia