Effects of temperature treatments on the heat production of starving chickens.
1. Heat production was measured for about 24 h at six temperatures from 2 to 35 degrees C on individually starved broilers that had been subjected to four treatments; these were acclimated or unacclimated to these temperatures, or to these temperatures for 12 h and to 22 degrees C for 12 h (alternated) during each 24-h period. 2. Response curves relating heart production and environmental temperature for the four different treatments differed significantly. Only the unacclimated birds subjected to the alternated temperatures increased heat production at 35 degrees/22 degrees C. Major effects of acclimation were observed mainly in the cold. 3. The relationship between daily endogenous nitrogen (N) excretion and heart production (mg N/kJ) was constant at the different temperatures, but acclimation and alternating temperature increased N excretion. 4. Evaporative heat loss was reduced by alternating temperature at the high temperatures, and by maintaining temperature constant in the cold.
D000064:Acclimatization; D000818:Animals; D001833:Body Temperature Regulation; D002645:Chickens / Q000502:physiology*; D004734:Energy Metabolism; D009584:Nitrogen / Q000378:metabolism; D013217:Starvation / Q000503:physiopathology / Q000662:veterinary*; D013696:Temperature
D009584:Nitrogen