202 



MAX KLEIBER 



amount of carbon dioxide produced and oxygen consumed the part 

 related to protein metabolism and from the so-called "nitrogen-free 

 R.Q." of the remaining carbon dioxide and oxygen calculate how much 



TABLE VI 

 Estimation of Heat Production from Fat and Carbohydrate Catabolism 



TABLE VII 



Example of Calculation of Heat Production by Indirect Calorimetry 



(Holstein cow 970 lb., 4th day of fast, Jan. 5, 1940) 



A. From Carbon and Nitrogen Balance 



Nitrogen lost in urine (measured) 



Protein catabolized (53 X 6.25) 



Carbon in cataboUzed protein (331 X 0.52) 



Carbon from protein in urine (calc. as urea) (0.43 X 53) ... 



Carbon from protein in respiration (172 — 23) 



Carbon lost as CO2 in respiration (1275 1. COo X 0.532) 



Carbon from catabolized fat (697-149) 



Fat catabolized (548/0.765) 



Heat production from protein (331 X 4.8) 



from fat (716 X 9.5) 



Heat production per day (from carbon and nitrogen balances) , 



53 g 

 SSI g 

 172 g 



23 g, 

 149 g 

 697 g 



548 g. 



716 g. 

 1589 kcal. 

 6802 kcal. 

 8391 kcal. 



B. From Oxygen Consumption 



Oxygen consumed per day: 1730 liters (0°C., 760 mm., dry) 



Heat production per day (from oxygen consumption) 1730 X 4.7 = 8132 kcal. 



fat and carbohydrate an animal has catabolized, and in turn what the 

 caloric equivalent per liter oxygen consumed and carbon dioxide pro- 

 duced are for various "nitrogen-free R.Q." values. Method and 

 results of such calculations are given in Table VI. 



One may estimate the heat production in kilocalories of an animal 

 in postabsorptive condition, catabolizing mainly fat, as 4,7 times the 



