The scene of cattle producers packed shoulder to shoulder in a community hall in south west Queensland has highlighted the growing fear that seasonal conditions are creating a 'perfect storm' for pimelea poisoning.
Winter rain over inland Australia has triggered a massive abundance of the annual native plant, which will be toxic to cattle as its flowers, seeds and seed tufts begin to die back.
Pimelea poisoning was once known as St George disease and it was in that district, in the rural locality of Begonia, that 120 people gathered to hear the latest advances in research and treatment, in order to arm themselves with knowledge for the coming storm of plants maturing.
Mitchell's Bim Struss was one of those and he said that as well as grazier surveillance and action to minimise contact in the short term, it would be important to continue to highlight pimelea toxicity as a priority national cattle production issue, through regional beef research committees, which provide direction to MLA research projects.
"It appears to me we need further funding for research to get to the heart of this scourge in our industry," he said. "Lets not forget pimelea occurs across a third to a half of Australia's rangelands, and it's spreading."
Several producers have already adopted using bentonite as a supplement, but Mr Struss said replicated field trials with control, ie untreated animals, were required to confirm its benefit and optimal rate of dosage to mitigate pimelea impacts.
He said that would need funding through MLA's Producer Demonstration Site funds or similar.
"We do need to further investigate the benefit of bentonite in a managed trial before we look to advocate the benefit to mitigate the impact of the pimelea toxin," he said.
The field day heard a presentation on using residual pre-emergent herbicides to control the native plant, but Mr Struss said it would be cost prohibitive over extensive areas and more useful in holding areas or paddocks such as a hospital paddock, that needs to be pimelea-free.
"Again, I think it is important trials are conducted to establish the veracity of the economics of these products," he said.
Mr Struss said he and others were living in hope of favourable outcomes from a computer modelling project developed between DAF, UQ Chemistry and QAAFI to investigate how the simplexin toxin molecule binds to the target protein, so that a way could be developed to prevent toxin uptake from the gut in cattle.
According to QAAFI toxic plant chemist, Professor Mary Fletcher, the seemingly irreversible binding to the enzyme is responsible for the cardiovascular impacts seen in pimelea poisoning.
"This project started as an industry placement of a UQ chemistry PhD student with DAF's Di Ouwerkerk and currently has no real funding," she said. "Understanding this binding may enable development of better binders/adsorbents targeted towards simplexin to prevent toxin uptake from the gut."
Prof Fletcher said resourcing was also needed to conduct field trials on residual pre-emergent herbicides such as tebuthiuron, metsulfuron-methyl and Tordon picloram granules, in hospital paddocks and along disturbed tracks.
"Pre-emergent herbicides prevent the germination of pimelea, and as such will not leave dead, and potentially toxic, plants that occurs with use of 2,4-D etc," she said.
MORE READING:
Sally Gall
Based at Blackall, CW Qld, where I've raised a family, run Merino sheep and beef cattle, and helped develop a region - its history, tourism, education and communications. Get in touch at 0427 575 955 if you've got a story idea for me.
Based at Blackall, CW Qld, where I've raised a family, run Merino sheep and beef cattle, and helped develop a region - its history, tourism, education and communications. Get in touch at 0427 575 955 if you've got a story idea for me.
