IFVING 



during which control measurements were made in the laboratory. 

 They were then subjected to outdoor exposure. When we first put 

 them out in the cold the temperature was about F. At first they 

 could not tolerate this cold on their feet and would howl, roll on 

 their backs and put their feet in the air. During subsequent expos- 

 ures of gradually increasing duration they evidenced cold injury, 

 particularly on the feet, ears and mouth. However, within a period 

 of two or three weeks these injuries began to disappear and they 

 were eventually able to tolerate temperatures as low as -30 C for 

 a full 24 hours with no apparent ill-effects. Such continuous expos- 

 ure was continued through the remainder of the winter, the summer 

 and into the early months of the following winter, when the experi- 

 ment was terminated. 



MORRISON: Were they eating meat or dog chow? 



HANNON: The diet was fairly high in protein; it was a mixture 

 of dry dog food, powdered milk, and fish meal. 



WEST: Did you find any difference in efficiency? 



HANNON: Do you mean work efficiency? 



WEST: No, efficiency of food assimilation; that is, the utiliza- 

 tion of the energy that you gave them. Did you get the caloric value 

 of feces, for example, to see if they were using all this food that 

 you were feeding them? 



HANNON: No, we did not. 



KLEIBER: I may have an answer to that, not for dogs but for 

 baby chicks. There we found a very consistent correlation between 

 food intake and temperature; namely, as we decreased the tem- 

 perature from 100 F to 95 F to 80° F to 70° F, there was a 

 consistent increase in food intake. There was also a decrease in 

 digestability. 



WEST: We found the same decline inefficiency with wiki birds. 

 I wonder if this is a part of the explanation for this increase in food 

 intake. 



168 



