Sheep Getting a New Way to Bare It : Ranching: A hormone that makes fleece fall out may do away with the back-breaking job of hand shearing.

One of Australia’s best-known images--the suntanned sheep shearer clipping fleece at breakneck speed--may soon become a piece of history.

Scientists have invented a hormone that causes fleece to peel off, saving the animal from an unnerving experience and cutting the amount of labor required--and the price of wool--by up to 25%.

Commercial use of the hormone may be as little as two years away, which could be good news for Australia’s troubled wool industry, with its 166 million sheep.

The genetically engineered hormone EGF weakens wool strands on the back of the sheep and makes the fleece peel off. EGF’s maker is IMCERA Group Inc. of Northbrook, Ill.

“Within about 10 days of injection, the animal is bare,” said Oliver Mayo at the animal production division of the Commonwealth Scientific and Industrial Research Organization, a research group.

“Sheep don’t like to be shorn,” he said. “It’s very traumatic for them. This is a lot easier on the animal, and you get this beautiful, evenly cut creamy-white fleece.”

EGF, which stands for epidermal growth factor, takes five to 10 days to weaken wool follicles. When wool resumes growing, the weak strands are pushed out and the fleece’s weight pulls it off.

Pitman Moore Australia Ltd., a subsidiary of IMCERA, has the marketing rights to EGF. Ron Hailing, a marketing manager at Pitman Moore, said EGF looks promising, but it is still being developed.

“We’re looking at ways of producing EGF in commercial quantities, which requires genetic engineering techniques, and we’ve done that,” he said.

But several obstacles must be overcome. The firm needs to develop new methods to harvest wool and manage sheep. Unlike shearing, which cuts off only the top layers of the coat, EGF sheds all of the fleece, right down to the roots. While this produces a continuous and higher quality coat, it also leaves the sheep naked and prone to injury and sunburn.

Sheep must therefore be wrapped in a “hair-net” jacket for six weeks, until new wool strands push through the skin surface and grow long enough to provide protection.

Because the breaks occur at different times in different parts of the body, the jacket must be put on immediately after injection. After six weeks, it is removed, and the wool can be peeled off as one continuous fleece.

Scientists say EGF will spell an end to the back-breaking work of sheep shearing, which increasingly relies on imported labor. What the effect of EGF will be on the number of sheep-shearing jobs remains to be seen, however.

Shearing accounts for 25% of the cost of wool production, amounting to $203 million a year in Australia, the world’s biggest wool supplier. It costs about $2.74 to shear the average animal, including labor and equipment. Rams, which are heavier and more aggressive, cost twice as much to clip.

The price of the EGF process, including the polypropylene jacket, must therefore be brought down to around $3.50 per animal to make the process viable.

“We believe we can . . . make the process commercially viable,” said Pitman Moore researcher Doug Pollock.

A spokesman for the government’s Wool Research and Development Corp. said the process was likely to be applied first to rams before it spreads across the industry.

Pitman Moore is working to lower production costs of EGF and reduce time and labor involved in putting jackets on the animals and taking them off again.

The company wants to develop lightweight, comfortable jackets that cannot be damaged by the sheep in the paddock and can be reused several times. It hopes eventually to see the jackets in use on most of the world’s 1.2 billion sheep.

“The resulting fleece is very good,” said Terry Leche at the Commonwealth research group. “There are no second cuts required for the spots that were missed, and it leaves the animal with a nice, smooth and very comfortable short coat. The process is quite trouble-free.”

But there are problems. When injected with the hormone, most pregnant ewes suffer abortions, and both males and females lose their appetite for a day.

Proponents say the hormone stays less than 24 hours in the sheep’s body and does not do long-term damage. Authorities have approved injected sheep as fit for eating, even if they are slaughtered shortly after injection.