Ready-to-wear fence for cows

It is the bane of every farmer's life. Someone carelessly leaves a gate open the next thing you know half your cattle have wandered off. Now scientists in Australia have come up with a solution: the virtual paddock.

After three years of research, they have developed a prototype fencing system using global positioning satellite (GPS) technology in a project that has been nicknamed Bovines Without Borders.



The system employs battery-powered collars which emit a sound to warn the cattle when they are approaching a virtual boundary line. If a cow wanders too near, the collar - which is fitted with a GPS chip - emits a warning hum. If the cow then continues on, it would receive a mild electric shock.

"It's like an electric fence except it's invisible," said Dr Andrew Fisher, of the Commonwealth, Scientific and Industrial Research Organisation (CSIRO). "The boundaries are drawn entirely by GPS and exist only as a line on a computer. There are no wires or fixed transmitters used at all. Importantly, what we're developing achieves the same result as a conventional fence but without the need for posts and wire."