Behavior and heart rate of heifers housed in tether stanchions without straw.

The effect of tether housing without straw was studied in eight heifers over a 12-week period. Resting behavior was recorded in the first and the twelfth week and heart rate (HR) in the twelfth week and compared to that of eight control heifers kept in a group on deep straw. Tethered heifers changed body position from standing to lying and vice versa significantly less often, and frequency of lying intention movements prior to lying down was significantly increased in tethered heifers. Correspondingly, latency between first intention movement and actually lying down was markedly increased in tethered heifers. HR was significantly higher in tethered heifers in all situations studied. During the lying procedure, HR increased in all animals so that the difference between the two groups remained unchanged. The biggest difference between groups was measured during the first lying intention, when HR was 125.2 +/- 9.4 in tethered heifers and 76.8 +/- 6.1 in controls. The results indicate that lying down in tether stanchions is aversive to the heifers and avoided as much as possible.