An automatic system to record foraging behaviour in free-ranging ruminants

Precise measurements of grazing behaviour are required to develop an understanding of the factors affecting the foraging behaviour of free-ranging domestic ruminants. An automatic, microcomputer-based system for the digital recording of the jaw movements of free-ranging cattle and sheep is described. Data recorded by the system can be processed to determine periods of eating and ruminating, and count the number of mastications and prehensions during eating and the number of mastications and boli processed during ruminating. The grazing behaviour of eight sheep (each in a different group) was recorded simultaneously by both the automatic system and one of several manual observers on four separate occasions. The overall index of concordance between the manual observers and the automatic system was 91.0%. However, the disagreements between the two recording methods probably reflect inaccuracies in the manual rather than in the automatic observations. The automatic system described in this paper provides a reliable means of recording various aspects of the foraging behaviour of free-ranging ruminants.