The Use of Radio Telemetry Devices to Measure Temperature and Heart Rate in Domestic Fowl

Abstract Since modern, intensive, husbandry systems may affect adversely both the productivity and welfare of domestic fowl, an understanding of the effects of short term stress is urgently required. Work has already shown what type of situations are liable to frustrate or frighten chickens and what the behavioral responses are likely to be. In the experiments described, these behavioral changes were correlated with physiological changes using radio telemetry techniques, which were particularly suitable since they resulted in minimal interference with the birds. Thin-film hybrid radio telemetry devices, designed to transmit temperature and electrocardiogram (ECG) signals, were attached to, or implanted in, domestic hens. The signals were picked up on a commercial receiver and recorded on magnetic tape. The ECG signals were analyzed on a small computer using an autocorrelation technique to give heart rate. Records were taken from undisturbed birds to get some idea of the normal range of temperature and heart rate during maintenance activities. Birds were then exposed to various visual and auditory frightening stimuli. Shank temperature was found to be a good indicator of the Alarm Reaction. Interesting differences in fear reactions were found between strains of fowl. ‘Flighty’ strains of hen showed far more avoidance and panic to visual stimuli than ‘placid’ strains. However, the heart rate of the so-called ‘placid’ birds rose almost as much and took longer to recover than that of the so-called ‘flighty’ birds.