HETEPOTHEBMY IN HOMEOTHEPMS 



KLEIBER: We measured that and found that there is a definite 

 increase in caloric output. 



HANNON: Well, the magnitude of the change in the beagles, at 



least, between this summer and winter is very similar to what 



o 

 you see in rats going into a 5 C cold room, thus suggestmg a 



similar caloric demand by the environment. In the cold, rats cer- 

 tainly exhibit a high rate of heat production, but as far as I know 

 the efficiency of food utilization has never been measured. 



IRVING: To get back to the remarkably high body temperature 

 that Dr. Johansen spoke about, I would like to inquire whether there 

 are reports of domesticated animals having reached similar high 

 temperatures? 



KLEIBER: Yes, Kibler and Brody* recorded rectal tempera- 



o o 



tures in Holstein cows as high as 108 F (42 C). Generally cows 



are in bad shape in a hot environment. 



FOLK: I might make another comment on continuous feeding of 

 dogs, since apparently not too many people have heard about it, but 

 some of the big kennels have been doing that for several genera- 

 tions. Sometimes, in experiments like those you do with white rats, 

 you want to have continuous food there. You do not want a perturba- 

 tion. If they have had food in front of them when they are quite 

 young they do not overeat. Occasionally there is one dog you will 

 need to eliminate because it does overeat, but they are rather quick 

 to learn to take just enough out of a feeder. 



HANNON; Our dogs in the study were two to four years old. 

 Thus, they were adults. Food was placed in front of them and left 

 for a period of one-half hour. But, as I mentioned earlier, they 

 would eat a little bit too much in the summer time and too little 

 in the winter time insofar as the maintenance of a constant body 

 weight was concerned. 



MORRISON: I wonder if the specific dynamic action of the food 



* Kibler, H. H. and S. Brody. 1953. Influence of humidity on heat exchange and 

 body temperature regulation in Jersey, Holstein, Brahman and Brown Swiss cattle. 

 Univ. of Missouri Res. Bull. 522-.14. 



169 



