Use of RFID active tecnology to monitor animals in open spaces

Monitoring livestock animals is a practice increasingly important in modern farms. This paper describes an active RFID technology and its application in open spaces, useful to track animals in their environment. The system consists of a beacon tag applied to the animal to follow, which sends an ID signal in given intervals at distances of up to 100 m. A device called “Marker” can define an area of interest using a loop antenna. When the tag is under the effect of this marked area, it adds the device ID in its signal allowing the instant determination of the position. The system was deployed in several situations involving different kinds of livestock animals, both in extensive and in intensive conditions (outdoor pigs, sows in collective pen, horses in paddocks with huts, dairy cows in free-barn). Recently the system has been tested on four fattening pigs kept in an outdoor concrete fenced area arranged with a wood hut. Functional parts of the breeding environment such as resting, feeding and drinking areas were bordered using markers. To test the precision of position data collection, videotape recording was used as mean of reference. The results of last trial showed acceptable localization performance with 5% of overall underestimation. Different levels of accuracy of this active RFID system depending on the type of animal, environment and functional areas monitored were confirmed. In particular, critical problems were highlighted in the behaviour of certain species and in the size of the active tag that remain, together with the cost, the main limitation to the use of this technology.