Growing up in regional Australia, it was not unusual to visit friends who lived on farms just out of town. In what seemed like a coincidence at the time, but in hindsight was probably a farmer taking advantage of free labour, there were always lots of jobs to do around the farm. Feeding livestock or driving headers or my personal least favourite - fencing! It has been some time since I last had to hammer a star picket into the ground. Fencing materials and installation methods have both undergone technology improvements, but it is still laborious work that comes with a high price tag. Some areas of Australia have very low stocking rates. In the Pilbara in Western Australia, the land requires 60 hectares for each cattle unit. As a result, the average pastoral lease size is almost 200,000 hectares. If you only fenced the perimeter, that would be at least 180 kilometres of fencing. At a cost of over $4000 a kilometre, that would be $750,000 just for installation. With harsh weather conditions and livestock that sometimes push the boundaries, literally, ongoing maintenance is also quite significant. The solution? Virtual fencing. With organisations such as the CSIRO and the University of Western Australia involved in the early stages of developing virtual fencing, there is now a large-scale trial being conducted in the Pilbara by Rio Tinto. A cow has a virtual fence collar fitted around its neck. This sensor has small solar panels, a GPS unit, speakers, a transmitter and a device that will impart a short pulse of high voltage to the cow if necessary. Sending signals from the device back to a satellite requires more power and precision so a farmer would install one or more base stations on the property to communicate with the collar. The unit receives GPS information from satellites so it knows exactly where the collar is. Communicating with the local base stations allows the exact position of the cow to be reported and also allows updates to be sent back to the virtual collar. The hi-tech farmer sits in front of a computer and draws a virtual map of where he wants his livestock to be situated. The farmer can spell certain areas of land to allow areas to recover or even use the collars to herd cattle in to smaller areas when required. Information on movement of cattle can be tracked and accurate numbers are always available. As cattle approach one of the virtual fences, an audible signal is used to alert the animal that they are approaching a no-go zone. If they continue on and cross the virtual fence, an electric pulse is used to deter any further movement. This would be similar to the jolt an animal may receive if they touched an electric fence. Trials indicate that cows only take 48 hours to learn that an audible warning means "turn around" to prevent feeling a shock. The RSPCA still has concerns about the wellbeing of the animal using such technology and most state governments are only allowing the technology to be used in trials at this stage but, at only $40 a collar, I can see the productivity gains changing the future of livestock farming. Of course physical fencing does more than keep livestock in. It also keeps predators, such as dingoes and wild dogs, out. Virtual fencing solves many problems, but keeping predators out is not one of them. More technology required!