Technology for farmers

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.