Recorded voice calls, other sounds used to steer cows in invisible fence tests
posted December 1, 2009
While a biological science technician for the USDA-ARS, Roy Libeau, now retired, adjusts a prototype
halter designed to direct cattle remotely.
Dean M. Anderson, PhD, herds a cow across a grassy range with clicks and calls of "come on, mama" and "come on, sweetheart."
His voice is broadcast from speakers on a halter around the cow's head. As the cow trots away, a calf follows, albeit with brief stops for bites of grass.
In the February 2009 test, Dr. Anderson equipped cows with a prototype neck saddle and stretch halter for a virtual fence system he hopes will eventually be used on ranches to remotely hold and herd cattle by combining GPS technology, recorded sounds, and, when deemed appropriate, electric shocks. The Ear-A-Round halters use speakers near the cows' ears independently or in concert to steer cattle or hold them within invisible boundaries.
"I think that the methodology is ready to be applied if somebody will simply manufacture the units," Dr. Anderson said. "Finding out the limits of usefulness of the device is going to require some further testing, but the concept of holding the animals behind static boundaries or holding animals in a polygon that can be moved spatially and temporally over the landscape has been shown to be successful with small numbers."
Dr. Anderson, a research animal scientist with the Department of Agriculture's Agricultural Research Service, has worked on the project for more than three decades and has used various prototype halters to control and herd cattle at the Jornada Experimental Range in Las Cruces, N.M. He is working with the Massachusetts Institute of Technology, which has developed the hardware and software.
Dr. Ulysses McElyea, who is a member of the Institutional Animal Care and Use Committee at New Mexico State University, said he thinks the virtual fence system is a fantastic concept for use in "wild, wide-open spaces" in the western U.S. He is an adjunct professor in animal and range science and an attending veterinarian at the university, as well as a small animal practitioner.
"The fenceless fence that Dean is working on, I think, is very, very appropriate," Dr. McElyea said.
Drs. Anderson and McElyea said the university's IACUC has approved the project.
Daniela Rus, PhD, a professor and associate director of the Computer Science and Artificial Intelligence Laboratory at MIT, said she had been performing similar research on remote cattle herding when she learned about Dr. Anderson's work in the field. She is now working with him to develop the electronic portion of the system.
Researchers at the USDA-ARS and MIT understand well what ranchers will need with respect to cattle biology, range ecology, and system electronics and software, Drs. Anderson and Rus said. She thinks halters will have to cost less than $100 each, and he thinks the equipment could be manufactured and sold at a "two-digit" price for each headset, depending on the bells and whistles included.
"Since we're talking about flocking, herding, gregarious animals, it is my opinion that we would not have to necessarily instrument every animal in the group if the object was to control the group, and this would reduce the cost of implementing virtual fencing," Dr. Anderson said. "However, more research is needed to determine what percentage of cows have to wear the instruments for the system to effectively move and control a herd."
The prototypes have been used to test the effectiveness of voice recordings, electronically generated noises, whistles, buzzing sounds, and various environmental sounds, Dr. Anderson said. He has studied reactions from cows, some of which have flicked their ears at noises that have caused others to run.
He added that, by determining the most effective sounds, cattle owners would ideally not have to apply any shocks, and suggested that, at most, shocks would be administered only periodically and immediately following audio cues to teach the cattle.
The cues start at whisper level and, if a cow ignores the cues, they can increase in volume to a physically uncomfortable level similar to that experienced when standing near a 747 engine during takeoff. Dr. Anderson said one study showed audio cues caused the animals' heart rates to jump less than did common environmental events, such as flocks of birds flying overhead.
The current components weigh about seven pounds, Dr. Anderson said, and the devices could be smaller when manufactured commercially.
The flat solar panels atop the current prototype electronics box will likely be replaced by convex panels attached to a belt that fits around a cow's neck, Dr. Anderson said. The devices could eventually use kinetic technology such as that used in self-winding wristwatches.
He envisions that the collars would replace internal barbed wire and electric fences, but not perimeter fences, on properties. However, the system is not intended to eliminate use of barbed wire in situations where compromising animal control would create health or safety risks for people or animals, Dr. Anderson said. And those implementing virtual fencing will have to accept some leaky boundaries as even animals with the halters can be unpredictable. He thinks the system will be most valuable in distributing animals over landscapes to avoid overuse of land and vegetation near drinking water, and underuse at boundaries.
Cow owners will also be able to play their own recorded hollers, songs, and sayings through the collars, providing animals with the familiar sounds of their owner's voice as they are moved, Dr. Anderson said. His voice is played for his cows as they are herded to the corral, where they are rewarded with cottonseed cake.
"Animals remember," Dr. Anderson said. "Whatever you do to an animal, you're teaching it something."
Welfare and applying the technology
Unlike some wildlife tracking system collars, the stretch halter used on the cattle is made of bungee cordlike material and the "saddle" sits loose on the animals, Dr. Anderson said. That allows room for growth and normal grazing, swallowing, and belching.
The halters are also designed to break away from the animals if they become caught on objects, Dr. Anderson said.
Dr. Anderson said the system also uses a less powerful shock than those from cattle prods or electric fences.
"Me being the guinea pig and hanging on to the electrode end of a 'hot shot' or touching an electric fence, versus me touching the electrodes of this device I've built, I can tell you that the device is much less severe," Dr. Anderson said.
He said nothing will replace the "insightful eyes of a human," and he hopes ranch workers will spend more time examining the livestock, vegetation, resources, and soil. Moving those workers into offices would be a disastrous application of the technology, he said.
Dr. Anderson envisions ranch hands using the technology would spend at least the same amount of time with the cattle as they traditionally have, but they would spend more time studying the animals and their environment than herding them.
"It's basically changing physical labor into cognitive labor," Dr. Anderson said.