Remote physiological monitoring of livestock - an implantable radio-telemetry system

摘要

During production and transportation livestock are frequently exposed to environmental stressors which may compromise both welfare and productivity. Assessment of the degree of physiological stress imposed by these challenges is important. Whilst measures of physiological variables made at intervals, e.g. by point sampling, yield much information it may be suggested that continuous monitoring and correlation with parallel records of conditions and events would provide greater insight in to the physiological demands imposed by the environmental stressors. A multi-channel, surgically implantable, radio-telemetry system (Tx) has been developed, therefore, for the continuous remote monitoring of deep body temperature (DBT) and heart rate (HR). The system is bi-directional allowing full control of the Tx even after implantation. All data are collected on to a personal computer for further processing, storage and analysis. The transmission range is up to 30 m and thus the package is suitable for use incommercial production and transport environments. The system has been successfully employed in studies of diurnal rhythms in HR and DBT and the effects of road transportation in poultry and calves. In studies on transported broiler chickens and calves container temperatures and humidities were recorded throughout commercial type journeys. Variations in HR and DBT and their temporal patterns were correlated with journey events and conditions. Overall mean heart rate was higher in transported birds thanin controls and DBT was also elevated. Increases in both HR and DBT were also observed in calves in transit. It is proposed that continuous, radio-telemetric, remote monitoring of physiological signals in livestock is a major advance in characterizing the effects of potential stressors in production environments and procedures.