Biology: How to Peel a Sheep

Armed with electric clippers, an ex -perienced sheep shearer can completely strip the wool from a sheep in three min utes. In Australia, where his specialty is a legendary profession as well as a sheer necessity, a champion shearer soon becomes something of a national hero.

And in the U.S., where he can earn a princely $12 per hour denuding sheep, the shearer contributes to the high cost of woolen garments. But the shearer’s days of glory may well be numbered.

As a result of research by Department of Agriculture scientists, an unskilled la borer can now equal the speed of a shear er by literally peeling wool from a sheep with his bare hands.

The bizarre idea for peeling sheep occurred to Geneticist Clair E. Terrill while he was studying the results of experiments with anti-cancer drugs. In tended to halt the growth of cells in malignant tumors, the drugs were also found to interrupt cell growth in the hair roots of test animals — including sheep — causing them to lose their hair temporarily.

The phenomenon was not lost on Terrill, who is chief of the Agriculture Department’s Sheep and Fur Animal Re search Branch at Beltsville, Md. If the effect could be produced only when the sheep’s wool was long, he reasoned, the fibers could easily be pulled, instead of sheared from the animal. And the un skilled farm labor needed for the simplified job would earn only about $2.50 per hour, sharply reducing costs to the wool industry. Taking up the project at Terrill’s suggestion, Agriculture Biologist Ethel Dolnick and Physiologist Ivan Lindahl began feeding varying amounts of a nitrogen-mustard anti-tumor drug to experimental sheep.

Too great a dose either killed or sickened the sheep, and too little failed to produce the desired effect. But the researchers soon discov ered that a dose of about nine milligrams for every pound of the sheep’s body weight produced just the right result. The drug affected the wool fiber only where it is produced, in follicles below the surface of the skin, and acted for about 24 hours before being dissipated by the body. During this period, cell growth was retarded, producing thinner than normal segments on each fiber before normal growth resumed. Six or seven days later, when these weakened segments of fiber finally poked their way above the skin, they could be broken easily with a slight pull.

Scientists found that they could then peel off the wool with no more effort than it takes to remove adhesive tape from skin.

The peeling process is painless to the sheep, avoids the occasional scratches or nicks left by shears, and assures an even cut of wool. Although researchers will continue to test for possible damaging side effects, the process seems to have done no harm so far to the wool or meat quality of properly dosed sheep. The new technique provides an additional fringe benefit for the sheep. If the wool is allowed to continue growing for as long as three weeks after the drug is administered, the constricted segment of the fibers is pushed about an eighth of an inch beyond the skin. Thus ranchers can not only peel off the wool evenly, but also leave a woolly stubble behind to protect the sheep against the elements.