Respiration in exercising fowl. II. Respiratory water loss and heat balance.
1. Respiratory water loss and rectal temperature were measured in domestic fowl running for 10 min on a treadmill at speeds of 1.24-4.3 km h-1 in air temperatures of 20 +/- 2 degrees C or 32 +/- 2 degrees C. 2. At given speeds the water loss at 32 +/- 2 degrees C was approximately twice that at 20 +/- 2 degrees C and the end-exercise rectal temperature was 0.5-0.8 degrees C higher. 3. At 20 +/- 2 degrees C, respiratory evaporation accounted for 10-12% of the total metabolic energy used at all speeds. At 32 +/- 2 degrees C, the fractional respiratory heat loss fell from 26.5% at 1.24 km h-1 to 17% at 3.6 km h-1. The fraction of the total metabolic energy stored as body heat rose progressively with air temperature.
D000818:Animals; D001833:Body Temperature Regulation; D005260:Female; D008124:Locomotion; D005082:Physical Exertion; D011200:Poultry / Q000502:physiology*; D012119:Respiration; D014870:Water Loss, Insensible