A natural protein in corn is the secret weapon behind AWI funded research into new opportunities for biological defleecing of sheep.
The protein generates a weakened zone at the base of the wool fibre but, unlike previous biological defleecing processes, this method enables the fleece to stay on the sheep without a net until the wool can be removed.
In the 1990's, research and development by CSIRO created Bioclip®, which allowed wool harvesting without the use of a mechanical handpiece.
Instead sheep are given a single vaccination of Epidermal Growth Factor (EGF) that causes a break to occur in the wool fibres.
The animal then has a net placed over them into which the fleece is shed about one week after the sheep is injected.
While Bioclip worked, there was little take-up by woolgrowers, mainly because the putting on and removal of the nets from the sheep made it a labour-intensive process.
However, there is potentially a new opportunity for biological wool harvesting based on the zein class of protein which is found in corn, and could enable harvesting without the need for nets.
Research by the University of Adelaide showed the corn protein weakens the staple of most of the fibres so that a mechanical removal device can break the fibres and remove the fleece without the need for cutting equipment.
"The important thing about this proved concept was that this treatment allows the fleece to stay on the sheep without a net - and that's revolutionary, and potentially could be a real labour-saving option for woolgrowers compared to Bioclip," an AWI spokesperson said.
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Compared to traditional shearing, biological wool harvesting also eliminates second-cuts and skin pieces and can reduce variability in wool fibre length.
This trial has provided AWI with the confidence to proceed to larger scale trials around appropriate dosage and timing of the treatment.
Professor Phil Hynd from the University of Adelaide said many millions of dollars have been spent on developing robotic shearing or biological defleecing alternatives with only one process (Bioclip) reaching commercialisation.
"The problem has been we have attempted to replicate the process of severing fibres like conventional shearing does," Professor Hynd said.
"For robotics this means ensuring a sharp cutter and combs travel very close to the skin with the potential for injury as sheep move.
"For biodefleecing the target has also been severing the fibres by stopping cell division in the base of the wool follicle, thereby momentarily stopping wool growth and causing the fleece to be shed."
The new treatment will allow the removal of fleece several weeks after the dosage and after a covering of wool has regrown under the weakened zone.
Experiments so far have seen a large number of sheep treated and managed under normal grazing conditions for up to ten weeks,
"There was no difference in wool loss between the controls and treated sheep," Professor Hynd said.
Professor Hynd said a thorough review of the biochemistry has been completed.
The next steps in the project are investigating preferred application and developing the mechanical devices for fleece removal.
The project will run over several years to check whether there are any negative impacts on wool growth and quality as well as animal growth and health.
"We are very excited by the progress we have made but do not underestimate the challenges before us," Professor Hynd said.
