Electronic (Fenceless) Control of Livestock

During June and August 1992, we tested a new technology designed to exclude cattle from specific areas such as riparian zones. Technology consisted of an eartag worn by the animal that provides an audio warning and electrical stimulus to the ear as the animal approaches the zone of influence of a transmitter. The transmitter emits a signal that narrowly defines the desired area of exclusion. Tests on cattle indicated that the technology is about 90 percent effective at excluding animals. This technology has been patented, and the Forest Service is pursuing ways to develop the product for marketability. During June and August 1992, we tested new technology to exclude livestock from specific areas, such as riparian zones. With this technology, livestock can be trained by means of an electronic eartag to respond to audioelectrical stimulation. The audio-electrical stimulation occurs when the animal enters the zone of influence of a signal from a remote transmitter installed in the area from which animals are to be excluded. The transmitter defines an area from which animals are to be excluded by emitting a continuous, coded signal of designated strength. Adult animals within the area wear an electronic eartag containing a receiver, an audio warning emitter, and a device to produce a small electrical stimulus to the ear. If the animal ventures into the exclusion zone, the signal is detected by the receiver in the eartag. The signal activates the audioelectrical stimulation modules in the eartag, thereby resulting in only an audio warning. If the animal remains in the area, however, electrical stimulation to the ear of the animal is invoked. If the animal exits the exclusion zone, no further stimuli are received. If the animal proceeds toward the transmitter, the signal from the transmitter again activates the eartag and the animal receives another audioelectrical stimulation. Built-in safety devices lock up the eartag after four audioelectrical stimuli are received, after which the eartag must then be reactivated by an unlock transmitter. Prototype eartags and transmitters were developed from specifications provided by the authors for tests on cattle in Texas and Nevada. Cattle and facilities were supplied by the Scott Petty Ranch in Yancey, Texas, and by Dean Baker Ranches in Baker, Nevada. During the test conducted in Texas, we learned that a short period of training is necessary to teach animals how to respond to the audioelectrical stimulus. After training, most responses were correct—animals …