ABSTRACT
We measured oxygen consumption
heart rate (HR), stroke volume (SV), cardiac output (CO) and mean arterial blood pressure (MBPa) of chickens during 15 min treadmill exercise at 0·5 ms−1 and 0·8ms−1 at thermoneutral (23°C), low (9°C) and high (34°C) ambient temperature (Ta); the vertebral canal was cooled to 34°C during the middle 5 min of each exercise period. 
pH and oxygen content 
of the arterial and mixed venous blood were also measured.
during exercise was not significantly affected by Ta. Spinal cord cooling produced definite increases in 
CO and SV during 0·5ms−1 exercise at 9°C; otherwise, effects of spinal cord cooling were not significant. HR, SV and CO were all linearly related to 
these relationships were unaffected by spinal cord cooling or Ta.Blood pressure did not increase during exercise.
and 
did not increase significantly during exercise. The arterial-venous 
difference was increased by exercise only at 34°C. The chickens generally hyperventilated at 34°C Ta compared to the other Ta values. No consistent effect on blood gases or on pH and 
of the blood could be attributed to spinal cord cooling.
