SCIENTISTS specialising in livestock parasites are applying nanotechnology to create improved formulations of flystrike insecticides that extends the periods of protection.
Silica nanocapsule particles less than a thousandth of a millimetre in size have proven effective in delivering the holy grail - a controlled release method for flystrike treatment.
The tiny tool means the chemical is protected from photodegradation and the risk of washing out in wool, University of Queensland research fellow Dr Peter James, project head, explained.
Flystrike costs the Australian sheep industry $173 million a year and the search for new methods of control is driven not only by the need for longer periods of protection but to counter the development of resistance to insecticides and to support the reduced reliance on mulesing.
The Australian Wool Innovation funded project is designing and testing the unique silica nanocapsule particles with surface spikes purpose-built to give prolonged periods of protection against both flystrike and lice.
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"Nanotechnology is increasing in leaps and bounds and being applied to all sorts of uses, particularly in the medical field," Dr James said.
"We've always been interested in controlled release for flystrike treatments. It is certainly the way the industry wants to go, with longer periods of protection and reduced labour inputs, as evidenced by the success of flea collars in dogs and insecticidal ear tags for buffalo fly in cattle."
Because high initial concentrations of chemicals aren't needed to provide extended protection there is less chance of residues and environmental contamination.
"In Australian production systems, with the sort of economies of scale we have, we need to be able to protect sheep over a long period of time," Dr James said.
"If we can formulate chemicals differently, we change how they work.
"With nanotechnology, we are extending the chemistries we already have, but also making other chemistries a possibility."
The research is also investigating the possibility of having the chemical release at times when there is increased flystrike risk.
Dr James said the careful choice of active ingredient can ensure minimal residues or off-target effects for the sheep.
"Nanocapsules offer new, labour-efficient options for managing flystrike and could also help counter the risk of blowflies developing resistance to treatment," he said.
Materials scientist Professor Michael Yu said UQ had patented the silica nanoparticles that feature a hollow cavity and a porous silica shell.
"We've tested a number of designs, but the most promising is a nanoparticle that has whisker-like spikes which cover the outer surface," Professor Yu said.
"These spikes help the capsules 'stick' to either the fleece fibres or to the blowflies."
AWI General Manager Research Dr Jane Littlejohn said nanotechnology had the potential to increase the range of treatment options available to woolgrowers.
The next stage of the research will be to move the study out of the laboratory and test the technology in the field.