MONITORING GRAZING BEHAVIOR OF CATTLE WITH AN ACCELEROMETRY-BASED ACTIVITY MONITOR AND GPS

摘要

Spatio-temporal information on the grazing behavior of animals can help farmers do the efficient management of the pasture and animals. For the purpose of establishing an easily monitoring system of grazing behaviors of cattle, we developed a simple method for discriminating the activity and location for eating from the other activities and locationsusing an accelerometry-based activity monitor, the Kenz Lifecorder (LCEX; Suzuken Co Ltd, Nagoya, Japan), combined with a global positioning system (GPS). The study was conducted in a mixed sown pasture (2.85 ha) located on a northeast slope (ca. 8.3°) ranging from 115 to 135 m above sea level. Four cows of 20 cows grazed in the pasture were fitted LCEX-GPS collars over the course of four days (June 14 to June 18, 2010) and were recorded the activity count and the location every 4 seconds and 1 minutes, respectively. We also observed behaviors of the four cows for 15 hours and classified the activities into eating, ruminating and resting every minute. Logistic regression (LR) and linear discriminant analysis (LDA) were applied to the dataset (LCEX and observation data) to distinguish eating and other activities (resting and ruminating). The LDA results showed a higher correct discrimination percentage for all cows (90.6 to 94.6%) than did the LR results (80.8 to 91.8%). Applying the LDA function over the whole period of LCEX data, the time spent eating averaged 443 to 475 minutes per day (30.7 to 33.0%). By using the locations obtained by the GPS collars, we determined the spatial distribution patterns of eating and other activities of cattle. During the daylight period, the cows mostly grazed in the lower-altitude area of the paddock, covering a wider area than at night. During the midnight, the cows spent most of their time in the higher-altitude area of the paddock, with less eating activity.