A review on the use of sensors to monitor cattle jaw movements and behavior when grazing

Abstract

Introduction. Precision Livestock Farming (PLF) is spreading rapidly in intensive cattle farms. It is based on the monitoring of individuals using different kinds of sensors. Applied to grazing animals, PLF is mainly based on the recording of three parameters: the location, the posture and the movements of the animal. Until now, several techniques have been used to discriminate grazing and ruminating behaviors with accuracies over 90% on average, when compared to observations, providing valuable tools to improve the management of pasture and grazing animals. However, bites and jaw movements are still overlooked, even though they are of utmost importance to assess the animal grazing strategies for various pasture types and develop future techniques allowing better estimation of their intake. Literature. The goal of this review is to explore the possibility of monitoring the individual jaw movements and the differentiation of bites in grazing animals. For this purpose, (1) the mechanisms of forage intake in cattle are explained briefly in order to understand the movements performed by the cow, especially during grazing, (2) the various sensors that have been proposed to monitor jaw movements of ruminants such as mechanical sensors (pressure sensors), acoustic sensors (microphone) and electromyography sensors are compared and (3) finally the relationship between jaw movements, biting behavior and forage intake is discussed. Conclusions. The review clearly demonstrated the abilities of mechanical, acoustic and electromyography sensors to classify the difference types of jaw movements. However, it also indicated a wide range of accuracies and different observation windows required to reach these accuracies when compared to the observed movement. This classification purpose could lead to a better detection of more specific behavior, e.g. bite detection, and their exact location on pasture.

Characterization of grazing behaviour microstructure using point-of-view cameras

“…Rows represent scale levels (behaviour units), columns represent hierarchical perspectives (dimensions, locations, structures, dynamics, and patterns). Patterns, at each scale, are generated by the distribution of frequencies, durations, rates, and volumes (based on the original conceptual model of ecological hierarchy of [24] and on contributions of [7,15,25]). https://doi.org/10.1371/journal.pone.0265037.g001…”

“…Additionally, it is difficult to predict how the presence of an observer may alter the behaviour of the grazing animal. The use of sensors such as electromyography, accelerometers, microphones, pressure sensors, and jaw switches (reviewed by [15]) may avoid the observer effect. However, despite conveying information on grazing patterns, sensors cannot provide information on forage selection.…”

Comportamiento de ingestión y consumo de forraje por vacas en pastoreo en clima templado. Revisión

“…La escala más pequeña de la dinámica de forrajeo es el bocado y su obtención se define como la colocación de forraje en la boca y su desprendimiento del resto de la planta por movimientos de la boca y de la cabeza (8,12) . Con movimientos de los labios, lengua y mandíbulas ocurre la aprehensión y acomodo del bocado dentro de la boca y con movimientos de la cabeza se obtiene la tensión para lograr la ruptura del forraje.…”

“…Figura 2: Escalas espaciales y temporales del comportamiento de pastoreo de herbívoros grandes (9,11,12) La escala espacial siguiente es la estación de alimentación, área en la que el animal selecciona y toma bocados con movimientos del cuello sin mover sus patas delanteras (14) . El nivel inmediatamente superior es el parche, que consiste en un conjunto de estaciones de alimentación (13) .…”

“…Sin embargo, la ganadería de precisión, que abarca el uso de herramientas tecnológicas para evaluar el comportamiento del ganado (28) , puede contribuir a tomar decisiones sobre la gestión en tiempo real y comprender mejor la relación planta-animal en los sistemas de pastoreo. Al respecto, existen diversos sensores y dispositivos que se han utilizado para el monitoreo de movimientos mandibulares y el comportamiento de ingestión de bovinos en pastoreo (12) .…”