ParaBoss News - February 2019 - Feature Articles

Fast Fact: Why Observation and Reporting Matters

A few months ago there was a piece on lice surveillance. The question is, what would you do if you found something apart from lice? The time was when sheep ked (Melophagus ovinus) and face/leg lice (Linognathus spp) were common, but they have almost disappeared with newer insecticides and mectin drenches. It’s worth getting them identified just to be sure, and in the case of ked the boffins may be interested in preserving an endangered species.

What if you found ticks on your sheep? Ticks are rare on sheep in Australia and the most common species (Haemaphysalis longicornis, the bush tick) causes little damage. It may be that a new species has moved into your area. They should be identified for that reason alone because worldwide ticks are vectors of some amazing and devastating diseases of both sheep and people. It’s just possible you have a genuinely exotic species carrying a genuinely new disease. Check out this great article by Bruce Watt (LLS, Bathurst) to understand why identifying ticks really does matter.

What are your needs for better parasite management services?

Feature articles

Do you want better parasite management services?…do the Australian Sheep Parasite Survey

by Alison Colvin, University of New England

All Australian sheep producers are encouraged to complete an online survey asking about the parasite control practices they used during 2018. Responses to the survey will remain confidential; identifying data will NOT be collected. >> Read more.

Give some thought to the timing of your strategic drenches; in some regions, they may be required now. 

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

Strategic drenches are designed, primarily, to reduce contamination at designated times so that pastures carry less contamination later in the season. There is wide variation between the regions in the timing of the strategic drenches so go to this page and then follow the links to the drenching guide for your state and region. For example, in Victoria a second summer drench is frequently given about this time, based on WECs. In Western Australia a second summer drench selects inexorably for resistance so that adult sheep are not drenched now, but should receive an autumn-break drench. 

A few things to keep in mind with strategic drenches. First, strategic drenching protects permanent pastures rather than crops or stubbles. Secondly, if you miss the boat the benefit of strategic drenches will be greatly diminished so plan well ahead and monitor for trigger levels. Third, be aware of the need for some refugia. Even if you routinely give a second summer drench it may be ill-advised if you’ve had an exceptionally dry season. Finally (a caveat rather than a principle), unseasonal rain or long springs may reduce the effectiveness of a strategic drench so make sure you monitor as suggested lest you get caught relying too much on the strategic drench. Peruse the guides and if uncertain consult a local expert. >> Read more.

Are you using the right flystrike chemical? 

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

The writer was contacted by a client concerned that a flystrike preventive was not “curing” struck sheep. Not surprising: dicyclanil does not kill maggots! When choosing your chemical there are three considerations, a) whether you need treatment and prevention, or one or the other, b) your preferred method of application, and c) special considerations. The link above answers most of the question, but it’s worth highlighting a few points. Although cyromazine has a claim for killing maggots, it only works slowly and is a poor choice if there are many struck sheep. Many producers love the convenience of jetting races, but be aware that only two chemicals (cyromazine and mectins) can be applied through them. Special considerations include Export Slaughter Intervals (ESI) and Withholding Intervals (WHI); check your treatments against your product marketing plans. If you are an organic producer there is only one acceptable product: spinosyn. >> Read more. 

Where do you stand on lice biosecurity? 

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

Have you noticed that some producers treat for lice every year? While it’s not easy to keep lice out of your flock, a systematic approach makes a world of difference. Of all sheep diseases, the risk of lice can be managed better than many others. A lice biosecurity plan increases the chance of eradicating lice and keeping them out. 

Essential elements for eradication include:

• Complete musters.
• Appropriate chemical, particularly if you have split shearing or treat close to lambing.

To stop introductions consider the following:

• State of the boundary fence (action according to the risk posed).
• Neighbours risk: sheep traders versus closed flocks. Merino versus XB—those XB lambs are second only to goats in their capacity to stray; if you are a lamb finisher, give plenty of thought to how you will keep your lambs at home.
• Your sheep introduction policy: don’t forget the good, old sheep health statement. Avoid saleyards if you can.
• Sheep to sheep transmission is a higher risk than non-sheep transmissions, such as tufts of wool on fences or shearers moccasins. >> Read more.

When should goats be drenched for barber’s pole?

Introduction by Paul Nilon, Nilon Farm Health, Tasmania

Barber’s pole is a real challenge in goats. Indeed, high-risk barber’s pole regions are problematic for goat production. For small holdings, one strategy is to use the FAMACHA system to assess anaemia. It works brilliantly, but is not applicable to large enterprises because of the labour requirement. This MLA article (and the webinar link at the end) explains how to use FAMACHA results, while visual learners may like this YouTube link. The big advantage of FAMACHA is you only drench animals that need it, rather than the whole mob. Moreover, animals that return consistently high FAMACHA scores can be culled as being less resilient. Always perform FAMACHA with a score-card in hand. >> Read more. 

Are your worm egg counting results up to scratch?

WEC QA program—Register now

For all laboratories, veterinarians, livestock merchandise/stock agents and individuals who do worm egg counts as a paid or complimentary service to others. >> Read more.