The average weight of the steer was 824 pounds. For purposes 

 of comparison, it is usual to compute results to an average live 

 weight of one thousand pounds. It has been shown that the main- 

 tenance requirement is approximately proportional to the surface 

 of an animal rather than to its weight, while the surface is approxi- 

 mately proportional to the cube root of the square of the weight. 

 Computed in this way, the maintenance requirement of this steer 

 for energy per thousand pounds live weight was: 



5-59 



= 6-50 The, 



The results of eight trials of this sort on three different ani 

 mals, none of which were fat, were as follows : 



Maintenance requirements of steers energy. 





THE MAINTENANCE RATION. 



As already denned on page 7, the maintenance ration is the 

 quantity of feed which will supply sufficient protein and energy in 

 available forms to meet the maintenance requirements of the body. 

 Obviously, the amount of the maintenance ration will depend 

 both upon the magnitude of the maintenance requirements and upon 

 the availability of the protein and energy of the materials compos- 

 ing the ration. 



The maintenance ration of protein. 



It seems to have been satisfactorily shown that a supply of di- 

 gestible protein in the feed equal to the amount broken down dur- 

 ing fasting is at least sufficient for a maintenance ration. As al- 



(9) 



