Sometimes you just have to be patient. USDA range scientist Tom Quigley and fellow researchers concluded that after more than a decade of studying the use of radio transmitters and receivers to control livestock movement.

The scientists are researching so-called fenceless grazing as an alternative to conventional fencing methods - under certain conditions.

"Research that we conducted in the early 1990s showed us that animals will respond," points out Quigley, based at USDA's Forestry and Range Sciences Laboratory in LaGrande, OR. "The challenge has been getting the technology to function properly and reliably."

With recent advances in technology, though, Quigley says fenceless grazing will likely be at the farm/ranch gate in the relatively near future.

Here's a brushup on fenceless grazing basics:

* Cattle are fitted with eartags containing radio transmitters and electrical stimulators with contacts touching the animals' skin.

* A portable, battery-operated transmitter is installed in the middle of an area where grazing isn't wanted.

* As the animal enters the exclusion area, the eartag picks up a signal from the transmitter and sounds an audio warning.

* If the animal continues to move into the exclusion area after the initial warning, it receives an electrical impulse. The impulses continue at regular intervals until the animal leaves the restricted area.

"In our earlier studies, we found that we could train 90% of the animals in about two days," says Quigley.

Eartag weight - 3.5-4 oz - presented a major problem in early studies. "Our target with a new prototype will be about 1.5 oz."

Transmitters used in early studies also had serious shortcomings. But later this year, Quigley and his research team will launch studies to test a prototype of a receiver-transmitter package developed by Kansas-based AgriTech Electronics, LC. Firm manager Bob Marsh says the test units will be ready in about six months.

"If everything goes like we think it will, we could have a commercial version of the product on the market another year or so after that," he says.

Marsh believes radio-frequency fencing technology will mostly be used in situations where it's necessary to exclude animals from small areas and/or for relatively short periods. For example, it could be used to keep livestock out of riparian zones or archaeological sites on public land. Or it could be used to fence off areas where a landowner has planted trees or is in the process of repairing a conventional fence.

"There will also be applications for managed (rotational or intensive) grazing," says Marsh, who, along with partner Jerry Schell, is also working on a version of fenceless grazing that makes use of global positioning technology.

While price for the radio eartag-transmitter packages hasn't been determined yet, Marsh says the product will have to be cost-competitive with traditional fencing to be viable.

"We suspect it will be like it is with computers and other electronic technology," he says. "Price will come down as more and more units are sold