Grower says curvature overlooked

Rueben HaleCountryman

Producers are “asleep at the wheel” on curvature measurement of superfine wool, according to Boyup Brook woolgrower Roland Ritson.

Mr Ritson, who with wife Anne runs superfine wool enterprise Grindon, said producers had been concentrating too much on micron and not enough on curvature.

The Ritson family has been producing superfine wool for more than 75 years.

“Spinning count has two major components, fibre diameter and curvature,” Mr Ritson said.

“The wool that produces the very finest cloth, with the best softness, warmth, elasticity and drape, has low micron and high curvature.

“We have not differentiated the best wools in the marketplace, and we are now suffering the demise of the best quality wool-producing Merinos, due to lack of profit.”

Mr Ritson said micron was easily measured and understood through all sectors of the industry, while curvature was not.

“We Merino breeders put too much emphasis on micron at the expense of spinning count, crimps per inch or curvature,” he said.

“Both have an adverse correlation to fleece weight, but curvature as well as micron can be overcome with careful and accurate measurement of all the economic factors and skilful selection, made much easier by accurate measurement and modern genetics.

“Many breeders are ignoring spinning count or curvature, or even selecting for bold crimp rather than weighing the fleece, because of the correlation with fleece weight.

“The Australian wool clip gets broader in crimp while low-micron bolder-crimped wool floods the fine wool market — it is easy to breed finer because of good micron testing. Broader crimp, along with colour, will cause more rain penetration, more fleece rot, more flystrike and more chemicals used.

“This will continue as long as we don’t use and promote accurate curvature testing.”

Mr Ritson said Sheep Genetics, through MerinoSelect, had been good at developing accurate breeding values to allow much faster genetic improvement.

However, he said it needed to improve the accuracy of curvature Australian Sheep Breeding Values by standardising, and factoring in, the method of measurement.

“Testing of curvature has become a major problem because we have not insisted that it be done properly and accurately,” he said.

“I am advised by a reputable, independent wool tester that it can be done accurately on the whole staple of wool, as with the diameter distribution measurement tool — OFDA 2000 — but it is not as accurate or repeatable when done on fragments of wool suspended in water as with the Laserscan.

“As soon as fragments are put into water, they start to straighten out. This is made worse by there being no standard solvent or lack of solvent in the water, so different laboratories use different solutions and get different results.”

Mr Ritson said wool classers generally did not separate wool on spinning count, because there was no incentive in the market.

“We at Grindon have had large amounts of individual testing done over many years on an OFDA 2000,” he said.

“Last year, both yearlings (average 14.4mu) and adults (average 15.5mu) mostly ranged between 80 and 110 degrees per millimetre and averaged 93 degrees/mm. These measurements correlate closely with visual spinning count.

“By contrast, the wool clip, averaging 15.5mu, when measured for sale on the Laserscan, the fleece lines ranged from 66 to 78 and averaged 71.8. Three bales selected as 70s and up, spinning count measured 71, 77 and 78 degrees/mm respectively.

“The Australian Superfine wool appraisal type was a step towards differentiating the best superfine wool, but it fails the majority of true superfine types because it excludes all dust colours, although curvature is far more related to the quality of the finished cloth than scourable colour.”

Mr Ritson said brokers chose not to include curvature measurement in buyers catalogues because those supplied by the Australian Wool Testing Authority were less accurate than visual appraisal.

“Buying has been dominated by early stage processors or top makers, for which low curvature allows faster processing, while the spinner and weaver is further separated from the auction floor,” he said.

Mr Ritson said there were large numbers of wealthy people in emerging economies who did not mind paying a premium for the very best product.

“Unfortunately, the AWTA has a monopoly on pre-sale testing and also has the patent of the Laserscan,” he said.

“Is this not a serious conflict of interest? Unlike the scales in our retail stores, there is no higher authority to monitor them.”

However, AWTA general manager for raw wool Ian Ashman said Laserscan technology was the best available. “We do not own the patent for this technology,” he said. “We provide customers with two other fibre diameter testing methods — OFDA 100 and Airflow — should they wish to use them.”

Mr Ashman said AWTA produced fibre diameter test results in accordance with international standards.

“We are independently audited by the National Association of Testing Authorities,” he said.

“The authority has spent a lot of time standardising the curvature method to improve the accuracy and precision of these test results.

“We have also ensured that curvature measurements are now included in international round trials, so it can be monitored and assessed by the industry.”

Mr Ashman said the organisation had also been working closely with the Australian Superfine Wool Growers’ Association to provide regular reports on the curvature measurement of superfine and ultrafine wools.

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