Use of Radio Frequency Identification Active Technology to Monitor Animals in Open Spaces

Recent testing of an active radio frequency identification (RFID) system within an outdoor fenced-enclosure housing four fattening pigs is described. The system is a modular active-RFID system composed by marker, reader and beacon tag. The enclosure was divided into three areas using three marker's loop-antennas. These areas were the pigs' feeding, drinking and resting areas. The duration in seconds verified by video recordings that individual animals attended in the zones outlined by the markers was compared with the duration acquired by the active-RFID system. The results indicate an acceptable accuracy of position-data, as overall 5% underestimation was achieved. Different levels of precision were achieved by the active-RFID system according to the feeding, drinking and resting areas monitored. In particular, problems were encountered due to the behaviour of the pigs surrounding the perimeter of the marked areas, the size and positioning of the tag on the pig's collar, and other software, hardware and calibration issues some of which may be overcome. These issues, together with the cost, are main limitation when using this technology.