North Dakota cattlemen have picked up on a method developed by Mandan veterinarian Dr. Don Hastings to make "do-it-yourself" eartags that keep pesty insects away from cattle at a fraction of the cost of commercial tags.

The Midway Vet Clinic, Mandan, funds a non-profit research foundation, called the Dakota Foundation for Animal Health, that looks into new money-saving livestock ideas. In addition to the eartag idea, the Foundation has also yielded a first-of-its-kind treatment for ringworm and a twinning shot for sheep that reportedly produces 20 percent more lambs per flock by virtually guaranteeing twin lambs.

Dr. Hastings says the eartag idea is catching on because "the leather insecticide tags work as well or better than commercial tags. Extension agents tested the tags last year against commercial tags in an 800-cow herd and found that the tags were equally effective, and that the homemade eartags were less likely to fall off." Dr. Hastings notes that 97 percent of the ear tags stayed in place on the test herd.

The idea is to use soft scrap leather cut into strips about 1 in. wide and 7 in. long. The strips are soaked in a 10 percent solution of an insecticide -- Dr. Hastings recommends a 10 percent permethrin solution -- and a hole punched about 1/2-in. from the end of the tag. The tag is attached to the ear with a nylon-type electrical tie that's snugged up fairly tight.

Hastings recommends treating the tags by stuffing 75 to 80 strips into a quart jar and filling it half full with insecticide. After 12 to 24 hours, the tags will be completely saturated.

"The tags can be reused again and again. The insecticide seems to lubricate them and keep them pliable," says Dr. Hastings, noting that if scrap leather, available at leather stores, is used to make the tags the cost can be even lower.