A robust computational approach for jaw movement detection and classification in grazing cattle using acoustic signals

Abstract

Monitoring behaviour of the grazing livestock is a difficult task because of its demanding requirements (continuous operation, large amount of information, computational efficiency, device portability, precision and accuracy) under harsh environmental conditions. Detection and classification of jaw movements (JM) events are essential for estimating information related with foraging behaviour. Acoustic monitoring is the best way to classify and quantify ruminant events related with its foraging behaviour. Although existing acoustic methods are computationally efficient, a common failure for broad applications is the deal with interference associated with environmental noises. In this work, the acoustic method, called Chew-Bite Energy Based Algorithm (CBEBA), is proposed to automatically detect and classify masticatory events of grazing cattle. The system incorporates computations of instantaneous power signal for JM-events classification associated with chews, bites and composite chew-bites, and additionally between two classes of chew events: i) low energy chews that are associated with rumination and ii) high energy chews that are associated with grazing. The results demonstrate that CBEBA achieve a recognition rate of 91.9% and 91.6% in noiseless and noisy conditions, respectively, with a high classification precision and a marginal increment of computational cost compared to previous algorithms, suggesting feasibility for implementation in low-cost embedded systems.