Temperature influences upon vascular dynamics in cattle measured by Doppler ultrasonography

1.Doppler-image ultrasonography was used to document vascular changes and blood flow rates of cattle (Bos taurus) under hot (32.7 °C) and cold (8.1 °C) conditions for 24 h.2.Blood flow rates in the caudal artery increased from 27.8 (−2 h) to 43.4 mL/min at 23 h when cattle were maintained at 32.7 °C.3.Cattle at 8.1 °C showed lower caudal artery flow rates after 23 h (29.3 at −2 h to 13.8 mL/min at 23 h), following a rate increase after the challenge.4.The ability of Doppler-image ultrasound to detect vascular changes due to ambient temperature demonstrates its use as a non-invasive tool for assessing environmental stress on hemodynamics.