Paraboss - September 2021 - Feature Articles

22 Jan

Here's a hook...

The hookworm of sheep or goats infects the small intestine. It is a stout worm (20 mm long) with a large mouth and a body that may appear to be hook shaped. It prefers warmer, higher rainfall regions. Hookworms may cause diarrhoea, anaemia and sore feet from infection at the site of larval entry.

Strategic drenching

Strategic drenches are drenches given at a critical time to reduce worm larval contamination of the pasture for the benefit of the whole mob, and/or drenches given at times when sheep are most susceptible to worm infection.

Timing and purpose vary between region and class, but the determination will typically be based around one of two time periods:

when development of eggs to L3 (infective) larvae is likely to be low on pasture (e.g., a summer drench in winter rainfall regions) or high on pasture (e.g., an autumn drench in summer rainfall regions)

when sheep are most susceptible to worms (lambs/weaners, or pre-lambing due to hormonal suppression of immunity)

These drenches are given regardless of average WEC (see drench decision guidelines for alternative drenching guidelines).

Strategic and Tactical Drenching (wormboss.com.au)

Breeding and selection

Spring brings the promise of warmer weather, blooming flowers, the Christmas countdown and, of course, ram-buying season. Here’s what you should consider before you purchase your next ram.

Select the best buys by looking for heritable traits that, when bred into your flock, will lower the susceptibility to breech strike without the need for mulesing. Breech and body wrinkle are highly heritable while dag, breech cover and wool colour are moderately heritable.

Breeding for low susceptibility to breech flystrike depends upon your region.

For regions where scouring doesn’t commonly result in dags:

Select rams with favourable ASBVs for wrinkle/ or low visual wrinkle scores
Score ewes with wrinkle and class out

For regions where scouring does result in dags:

Follow the above recommendations and choose for dag ASBVs.

Long term breeding plans to avoid flystrike (flyboss.com.au)

Australian Sheep Breeding Values (flyboss.com.au)

ParaBoss WEC QA underway

The 2021 program is underway with 54 businesses and 152 operators registered to assess the accuracy and variability of their worm egg count results.

The inaugural round in 2019 highlighted an alarming number of operators—nearly 30%—did not meet the criteria for either accuracy, variability, or both.

Sheep producers using worm egg counts can have confidence that their WEC provider is giving useful results if they are accredited by ParaBoss and listed on the WormBoss Service Providers pages.

Unfortunately the 2020 round did not go ahead due to COVID freight delays. The list of accredited WEC providers will be updated with 2021 results once they are finalised later this year.

it’s shearing time, should I still treat my sheep?

As producers are getting prepared for a spring shearing, many ask: “if I haven’t detected any lice in my mob, should I still treat for lice?”

That answer depends on a few factors, including how long you have had the sheep, and whether you have any strays in the mob. Remember, it takes ~6 months or more to see a lice infestation.

If you introduced sheep less than six months ago, apply an off shears/short wool treatment at shearing. The same application advice applies for mobs that have had strays – keep these mobs isolated for at least 6 months’ wool growth.

If you introduced the sheep more than six months before sheering, haven’t had any strays and haven’t noticed any rubbing, you generally won’t need to treat.

If you’re unsure, ParaBoss and LiceBoss have some great step-by-step tools which prompt you with specific but simple questions and then, based on your answers, generates a PDF guide you can save and/or print.

For general lice treatments use LiceBoss Treatment Decision Guide

For ewes with lambs at foot use Lice Treatment for Breeding Ewes and their Lambs

Timeframes to keep in mind:

Off shears treatment applied within the 24 hours of shearing

Short wool treatment applied 2-6 weeks after shearing

Treating Lice (liceboss.com.au)

Drench decision guides

Just as sheep require a drench plan which can include strategic and tactical drenching based on the timing of application, goats also require a plan.

The Drench Decision Guides are even tailored to the typical considerations applicable within your region. Simply answer the easy-to-follow questions and download your individual guide. In some instances, a current WEC may be required, so it’s advisable to complete a test.

And if you only have a small number of goats? To keep the process streamlined goat owners who only have a small number of goats, and who are prepared to monitor and treat goats individually, can use the Australian smallholders version

Goat Drench Decision Guide Solve Your Current Worm Problems - Drench Decision Guides (wormboss.com.au)

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