If building fence isn't your favorite pastime, there's good news. Within a year, “virtual fences” — where animal movement is controlled by radio frequencies transmitted to an eartag — may be commercially available.

Oregon researcher Tom Quigley was among the first to test this technology on cattle 10 years ago. Quigley hoped to use it to keep livestock off riparian areas. Here's how it worked:

Cattle wore eartags, each containing a radio receiver and audio and electrical stimulators. A portable, battery-operated transmitter was installed in the area where grazing wasn't wanted. If the animal entered that area, the eartag picked up the transmitter's signal and gave an audio warning. If the animal didn't retreat, it received an electrical shock. Shocks continued until the animal left the restricted area.

In his research, Quigley says 95% of the animals stopped grazing in the exclusion areas, most of them trained within two days.

The objective of today's research on the technology is to make it a cost-effective alternative to traditional fences, says Bob Marsh.

Marsh works with the Kansas-based company AgriTech Electronics, which has two commercial products in development. One, based on Quigley's research, would involve ground-based transmitters. The second would utilize GPS satellites to establish a boundary and monitor the animal's location.

Both systems would apply audio and electrical shock stimulation to the animal through an eartag if it gets too near the established boundary.

Marsh reports that the eartag and ground transmitters could be on the market within a year. The GPS units could be available in two years.

“One of the challenges in bringing this technology to the market is the development of a lightweight battery for the animal's eartag that will last as long as a grazing season,” Marsh says.

He says initial applications will likely be for research, where extra cost is justified. Long term, his company hopes to offer radio frequency eartags for about $25/tag.

Dean Anderson, a USDA-ARS animal scientist, is also studying virtual fence technology at the Jornada Experimental Range in New Mexico. He's working with a solar-powered unit that receives radio frequency signals from GPS satellites and gives a variety of audio and electrical cues to the right or left side of the animal, rather than just one sound or one shock.

He, too, hopes an eartag in the “double-digit” price range will be made available.

“The real value of virtual fencing will be in managing stocking density and animal distribution in real time,” says Anderson. He foresees the concept as a prescription grazing tool used to move animals to specific locations.

“We're not going to put conventional fences out of business. The exterior boundary will still need to be fenced with wire to keep livestock off roads and railroads,” Anderson says. “This technology is not perfect at containing animals because animal behavior is not 100% predictable.”

Still, the applications look promising, and wireless fences should reduce arguments over who has to open and close the gate.