Sex differences of Japanese quails in response to acute cold exposure. Changes in thyroid activity and blood glucose level.

Sudden exposure of Japanese quails to cold (-1 to -3 degrees C) decreases the skin temperature during 0.5 to 3 hrs without any effect on the deep body temperature. The fall in skin temperature was about two times faster in males than in females. This indicates greater resistance to cold of females in comparison with male quails. Greater resistance to cold was accompanied by an increase in thyroid activity and earlier decrease in blood glucose level which may suggest that mobilization of these compounds for thermogenesis processes is faster in females than in males. In female quails sudden cold exposure prevents a decrease in the T4 concentration in blood due to handling stress.