A group of Federation University scientists are undertaking important research that may be a game changer in protecting sheep from worms.
The Mount Helen-based researchers are developing a field test - similar to a rapid antigen test - to find out an individual animal's worm load or resistance.
Trials have already begun on some Victorian farmers, and the researchers are calling out to farmers to help with the ground-breaking research.
Federation University lecturer and research academic in animal health Sarah Preston is leading the study with a research team including PhD student Leni Horner and Honours student Victoria Chew, along with Professors Michael Stear and David Piedrafita, who are assisting with the research.
Dr Preston said determining worm resistance via a saliva test had its benefits, including being a simplistic way to test.
"A lot of the research done into understanding the immune response to worms was done in the 80s and early 90s, and that was obviously when the wool market was really strong," she said.
"A lot of the papers that I rely on are published come from that era, so a lot of that work is really valuable and hasn't made it to the farm gate.
"I think there's a lot of research where they've looked at different immune markers in sheep that have been bred for worm resistance and biomarkers that have been validated, but they're staying in the academic literature."
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Dr Preston has written and published 30 peer-reviewed papers about animal immune response to parasitic worms and tracking resistance to drugs that treat worm infestations.
And while saliva-based tests have been developed and used in other parts of the world, it isn't available in Australia, but Dr Preston hopes further research can eventually translate into an actual product that farmers can use.
"We know that sheep will produce antibodies against worms, and resistant sheep will produce a lot more of them," she said.
"In New Zealand and the UK, they [have developed] a test that farmers can access to measure this marker and then incorporate into their breeding scheme.
"In Australia we don't offer that for some reason, so I think there's a lot that we can do in this area already just drawing from that existing knowledge."
Dr Preston also said markers of immune response are a better way to try and prevent worm infections in sheep because they can be targeted to specific regions of the country.
"I guess when you think of markers of infection, such as worm egg counts for Barber's Pole worm are really good correlation to the actual adult worm burden," she said.
"But for other worms that are more common in Victoria, like the more common scour worm, it depends on timing where the number of eggs in their faeces correlates well with the actual burden in the sheep.
"Whereas if you look at immune markers, they correlate much strongly with overall immunity, so that's one advantage of looking at immune markers instead of markers of infection.
Technology will also form much of her research, with researchers fitting accelerometers to sheep and using algorithms to understand how worm infection can affect the causal behaviour of sheep.
The collar accelerometers can pick up movement, idling, head movement and ruminating.
Dr Preston says this is furthering work found in earlier research papers that sheep with worm infections tended to walk more and travel to water sources more regularly.
One of the farmers taking part in the trial is Elise Kealy, Edenhope, who owns Curlew Merino stud along with her commercial farm.
She said her stud decided to participate in the trial because "worms cost individual farmers money".
"Some of that comes from the cost of treating the worms be it labour or drenching, but the majority of the cost comes from things like production losses, sheep not gaining weight, not growing wool, not milking as well, mortality and so forth," she said.
"In our stud, we select heavily for sheep that are resistant to worms, and we are always looking for a better way to identify these animals.
"It's relatively expensive, and it also requires a mob average to get to 250 or 300 eggs per gram."
Ms Kealy said if her stud had a more sensitive way of identifying animals susceptible or resistant to worms, it would have better outcomes.
"I've only been home on the farm 10 years and when I came home, my dad had already been selecting for worm resistant sheep, so we are very fortunate on our farm even though we're in a high rainfall area that most of our sheep are only drenched once a year," she said.
"However, if we continued to select for worm-resistant sheep, we could cease drenching altogether and the production losses that go with the need to drench.
"But compared to other farmers we drench significantly less, and I think there's an opportunity there for other farmers to also benefit from identifying worm resistant sheep better."
Any farmers or studs who wish to participate in Dr Preston's research can contact her at Federation University.
