Use of Inertial Measurement Unit of a Mobile Device to Discriminate Cattle Grazing and Ruminating Behaviours on Pasture

Precision livestock farming is emerging in the wake of the technological developments in remote sensing and motion monitoring. Tools are developed to allow accurate real time monitoring of the individual cattle behaviour in a quest to improve the management of pastures. Studies have shown the relevancy of accelerometers in the analysis of behaviour using dedicated devices. Accelerometers are located either close to the mouth or jaw of the animal or on its forehead or neck. Records are usually performed at low frequency (<1Hz) and most studies classify behaviours using neuronal networks or multivariate statistical approaches, with little consideration to the animals’ actual movements. Inertial measurement units (IMU) in consumer mobile devices are specifically developed to record accurately user movements. Besides 3D-accelerometer, they can include 3-D rotational speed sensors, 3-D magnetometers and GPS. Optimised power consumption offers significant autonomy. Data directly acquired from the sensors and IMU signals from build-in proprietary algorithms can be recovered using user-friendly low-cost applications. Moreover, mobile devices can store or communicate information by wireless in real time at high frequency.
As movements of cattle are in the same range as humans, this study investigates the relevancy of mobile devices IMU signals to discriminate main behaviours of cattle on pasture.