The effect of short term thermal stress on the heart and respiration rates of conscious and anaesthetized chickens.

Heart and respiration rates were measured in eight 6-week-old, White Rock chicks at different ambient temperatures: 24--26 degrees C (neutral), 6.5--8.5 degrees C (low) and 3,95--43.5 degrees C (high). The animals were exposed to these temperatures for 10 min. In both groups the low ambient temperature did not influence the respiration rate, whereas the high temperature caused a significant increase of the respiration rates both in the conscious and anaesthetized birds. In both groups no significant changes in the heart rate at different temperatures were found. Statistically significant differences in the heart and respiration rates between the conscious and anaesthetized chickens were noted only at the low environmental temperature.