The Evolution Of Virtual Fences: A Review
This articles reviews the history of virtual fences and discusses their use to manage “free-range” farmed animals. The article identifies several approaches to the development of such systems and their implications for farmed animal welfare.
A virtual fence is any structure serving as an enclosure or boundary without a physical barrier. Used in the management of free-range farm animals, these systems have the potential to reduce cost and allow the management of areas that are not otherwise manageable. In addition, they can enhance ecological management and improve management practices “by turning manual labor into cognitive labor.”
Virtual fences can be divided into three categories, those that contain animals in a designated are by using animal-borne devices, those that contain animals without placing a device on the animal, and those that keep animals apart by using a remote gathering device.
Important animal welfare considerations of these systems include energy use of the device and the development of a system that the animals can easily understand. Few devices are currently available on the market despite a large number of patents having been filed.