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ParaBoss News - November 2019 - Feature Articles

Old world screw-worm maggots and fly. Image Alan R Walker
Old world screw-worm maggots and fly. Image Alan R Walker
How fast are your lambs really growing?
How fast are your lambs really growing?
The Nigerian Dwarf goat has high resistance to barber's pole worm. Image Heather Lion
The Nigerian Dwarf goat has high resistance to barber's pole worm. Image Heather Lion


Fast Fact 

We can do without the screw-worm fly! 

Our northern neighbours are home to the old world screw-worm fly (Chrysomya bezziana). Maggots of this fly infest open wounds on all livestock species and even humans. If it (or its cousin the new world screw-worm fly) got in and established in sheep grazing areas, it could challenge sheep production as seriously as conventional flystrike. Screw-worm flies are attracted to almost any wound, so even meat sheep would be vulnerable. Be on the lookout for unusual 'screw-like' maggots in wounds on any species of livestock. >> Read more.  

Feature articles

So, how fast are your lambs really growing? 

Introduction by Paul NIlon, Nilon Farm Health

Talk at the pub (immediately after church, of course) is that prime lambs grow very fast—on everybody’s place, every year as a matter of fact. Indeed, the pub chronicle is that nobody has lambs growing at less than 200g/day! So, how come there are still so many spring lambs for sale in June and July? The best info comes from the survey work of Ian Carmichael in the early 2000s. Average growth rates are way less than 200g/day, and worms play an important part in this underperformance. Read Ian’s executive summary on the MLA website. Scroll to the bottom and open the link to AHW.045. >> Read more.

Are your sheep like armadillos? 

Introduction by Paul NIlon, Nilon Farm Health

Dermo (lumpy wool) is a disease, almost exclusively of Merino sheep, that has maximum impact on sheep less than 2 years old. The storybooks tell us there is no strain difference in susceptibility between different breeds of sheep, but this writer has never seen it in Saxon or Saxon Peppin sheep, nor in South Australian Merinos (maybe because there are so few left): go figure. The thing is, it can be a major fly attractant, and it can also diminish the effectiveness of fly and lice treatments. >> Read more.

Not all itchy sheep have lice

Introduction by Paul NIlon, Nilon Farm Health

Back in the day when the world was young (and Bob Hawke was telling us to take a day off to celebrate the America’s Cup win), itch mite (Psorobia ovis formerly Psorergates ovis) was still a problem. This mite is still around today albeit in low numbers and usually not in flocks exposed to ML anthelmintics. Sheep tend to rub a lice infestation and bite at an itch mite infestation. In the early stages of an itch mite infestation, yellowish crusts form and the fleece is moist and matted. Biting deranges the fleece along the sides of the body and down the thighs where sheep can reach. Tufts of any pulled wool tend to become twisted and pointed. >> Read more.

Getting around their worm susceptibility

Introduction by Paul NIlon, Nilon Farm Health

WormBoss notes make frequent mention of breeding more fly and worm resistant sheep. Well, what about goats? Given their troublesome susceptibility to worms, and their capacity to promote anthelmintic resistance because of rapid metabolism of drenches, breeding resistant goats seems a logical road. In comparison with sheep, the heritability of worm resistance in goats is poorly understood.  Worm resistance (measured by WECs) is likely less heritable than in sheep, but more research is needed. Some breeds (e.g. the Nigerian Dwarf goat) have high resistance to barber’s pole worm, so with time and imagination results will come. Follow this link to look at breeding more resistant goats and for information on Kidplan (sounds like a government childcare initiative). >> Read more.


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

Tasmania
Western Australia
Queensland
Victoria
New South Wales