Suitability of a commercial low-cost biologging system for monitoring movement, behaviour and heart rate of grazing dairy cows

This study explored the suitability of a commercial biologging system incorporating GPS and heart rate (HR) sensors to monitor grazing cattle’s movement, behaviour and heart rate. We preliminarily tested the GPS accuracy with stationary tests and then monitored six dairy cows grazing in an alpine summer pasture for 20 days and nights. We trained a random forest model on direct observations to infer cows’ behaviours (resting, grazing, walking) from GPS movement data. We associated each GPS position with the HR (beats per minute - bpm) mean and maximum-minimum difference in the 120–second interval preceding its acquisition. The GPS sensor showed high accuracy (positioning error lower than 2 m in open sky-view and 3 m under tree canopy cover) and efficiency of position acquisition of 95% after excluding outlier positions. The efficiency of HR data acquisition was lower, peaking at 77% during daytime activity and dropping to 50% during night-time resting. The HR mean and the maximum-minimum difference were lower during resting and at night and higher during grazing, walking, and daytime. They also increased with slope and Temperature Humidity Index (THI). This study indicates that this commercial biologging system is suitable for short-term monitoring of animals’ movement, behaviour and physiological responses to varying pasture and climatic conditions, offering insights for livestock management in alpine summer pastures.