Comparison of video recording and a portable electronic device for measuring the feeding behaviour of individually housed dairy goats

A detailed knowledge of chewing behaviour is important in understanding the factors that can affect digestive function in high producing ruminants. The aim of this study was to compare chewing behaviour either measured with a portable automatic system (APEC) which records jaw movements or obtained by scan sampling video analysis in 12 individually housed dairy goats. One hour and daily time-intervals were used for the analysis. APEC and video showed better agreement for 1 h than for daily time-intervals but a very high individual variability was observed for all the parameters measured. Daily duration of rumination seemed to be assessed better by the APEC than by the video because it is sometimes difficult to determine if the goats are resting or ruminating on the video. Daily duration of intake was however assessed better by the video because the automatic recorder interpreted all oral behaviours as intake. However, total chewing time is directly related to the amount of saliva produced which an important factor in ruminant nutrition. The APEC allows continuous recording of activity independently of the animal's position in the pen or in a group or at pasture where animals cannot be filmed, however the device can be easily damaged by the animals. Video cannot be damaged by the animals but it can be difficult to determine the animal's activity if the animal is lying-down or not facing the camera, or in a dark part of its pen. Both systems were relevant to measure chewing behaviour of stall housed dairy goats, and to study the daily time-budget of feeding behaviour but results have to be interpreted carefully.