Healthy progress on test for follicle density

SA research puts wool follicles under the microscope

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NEW TECHNOLOGY: Merinos at the University of Adelaides Roseworthy Campus are being scanned using the medical imaging technology.

NEW TECHNOLOGY: Merinos at the University of Adelaides Roseworthy Campus are being scanned using the medical imaging technology.

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MEDICAL imaging technology found in most major hospitals could help woolgrowers easily identify at a young age those sheep capable of producing higher yielding, whiter wool. The research is being conducted here in SA.

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MEDICAL imaging technology found in most major hospitals could help woolgrowers easily identify at a young age those sheep capable of producing higher yielding, whiter wool.

An Australian Wool Innovation-funded project, being conducted by Adelaide-based researchers, is using optical coherence tomography, which is commonly used to visualise eye disease and heart disease in humans.

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Adapting it to livestock, they are gaining images of wool follicles in the skin of sheep.

Chair of Biophotonics at the Centre of Excellence for Nanoscale Biophotonics, Robert McLaughlin is leading the project and is hoping to develop a hand-held scanner where wool density can be determined in the yards simply by pointing and clicking the device at the sheep.

"We are using standard medical technology and taking it where researchers never dreamed of to solve problems in the livestock industry," he said.

"It turns out if we scan the animal's skin using this technology we can clearly see the individual wool follicles in a small spot and count them, and also get an estimate of the diameter of each of the wool shafts."

It turns out if we scan the animal's skin using this technology we can clearly see the individual wool follicles. - Prof Robert McLaughlin

Prof McLaughlin says the only measurement for wool density is an invasive skin biopsy test which costs more than $200 an animal and must be analysed in a laboratory.

He hopes results will be available in real time using the high resolution medical imagery.

LOCAL TRIAL: Researcher Robert McLaughlin is using medical imaging technology to determine wool follicle density in the skin of sheep. Photo: Naomi Giatis

LOCAL TRIAL: Researcher Robert McLaughlin is using medical imaging technology to determine wool follicle density in the skin of sheep. Photo: Naomi Giatis

Initial scans undertaken on sheep at the University of Adelaide's Roseworthy Campus have produced results very close to the biopsies which have been taken at the same time.

A small area has been clipped and then shaven on the hip to access the skin of each animal scanned.

The project team are also working with machine vision researchers at University of Adelaide who are using these images and measurements to develop a machine that gives a single number reading for wool density.

The initial research has been undertaken on older sheep, but as they finesse the procedure they hope to test younger sheep.

UP CLOSE: A scan of a Merino sheep with the black dots representing individual wool follicles.

UP CLOSE: A scan of a Merino sheep with the black dots representing individual wool follicles.

"We know the density of wool follicles is pretty well set before they are born, it is largely down to genetic factors, so we should be able to do this on young sheep," he said.

"We are just getting the science right and then we will pull it back to doing younger and younger sheep - that is where the payoff will be biggest, knowing the best and worst sheep before their first shearing."

Prof McLaughlin says they have been able to get a good image at the hip of the animal as the sheep does not move too much, but the project will look at a range of locations across the sheep's body to find the most reliable spot.

The optical scanning technology, which provides images up to a millimetre under the skin's surface, is also able to see blood vessels.

The project is also investigating whether there is a link between the number of blood vessels in a certain area on a sheep and wool cut.

"Sheep that have more blood vessels may be better at growing wool faster and in humans blood vessels regulate temperatures, so could that also be the case in sheep?" he said.

Prof McLaughlin is optimistic they will be ready to test a hand-held device for measuring wool density with early adopting stud breeders within two years, as long as they can secure follow-up funding.

"The AWI funding is going to allow us to establish how we do this, is this viable and within the project we will have a plan of how to take it forward," he said.

A discussion between Prof McLaughlin and Mid North Merino breeder Andrew Michael, Leahcim stud, Snowtown, was the catalyst for the research, after Mr Michael saw medical staff shaving off hair on humans ahead of OCT tests.

Mr Michael sees increased profitability for studs and commercial flocks being able to easily access wool density data on their sheep

"Paraway Pastoral, who I do some consultancy work for, have done some sums and worked out if they were able to do all their ewe lambs at eight months in the race and use that to select only those with the highest fleece density with a high degree of accuracy, they could have saved feeding some sheep 14 or 15 months during the drought by knowing which ones to sell off," he said.

"That information is relevant not just for one year, but for five years or the life of the animal."

Leahcim recently calculated the fleece density of more than 1200 stud ewes on-farm by looking down at each animal's wool under a microscope and counting the follicles.

Mr Michael says they found there were big yield lifts from improving wool follicle density.

Importantly, he says they found there was no negative correlation between the sheep with more wool follicles and desirable carcase traits.

"As long as we also select for staple length, we are increasing the volume of wool we have. It is finer wool and higher-yielding wool - the impact on wool production is huge," he said.

"The more fibres the less suint per fibre, so another big plus is whiter wools which handle rainfall.

"Wool production and yields in the Australian sheep flock are down not just because of the drought, the Australian wool clip yields have been declining for the last 10 years.

"If we could add 5 per cent on the yield with the same number of kilograms of greasy wool, we would be exporting millions of kilograms of higher yielding wools and this would have a massive impact on freight and processing costs."

Details: Rob.McLaughlin@adelaide.edu.au

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