MAINTENANCE THE ENERGY REQUIREMENTS 303 



Summary 



390. For convenience of reference, the average results re- 

 garding the energy required for the maintenance of the com- 

 mon species of farm animals as recorded in the foregoing pages 

 are brought together in the following table. For live weights 

 other than those stated the maintenance requirement may be 

 computed in proportion to the surface in the manner described 

 in Chapter VII (347). 



TABLE 54. ENERGY REQUIREMENTS FOR MAINTENANCE 



As pointed out at the beginning of this section (376), the 

 foregoing figures express an economic rather than a physio- 

 logical requirement for energy. Besides the absolute energy 

 requirement in a state of complete rest, they include the energy 

 expended in divers forms of incidental muscular work, of which 

 one of the most important, in farm animals, appears to be that 

 of standing (349). The average for swine was obtained from 

 experiments in which the animals were lying during most or all 

 of the time. The average for cattle, as noted, has been com- 

 puted to twelve hours standing, while that for the horse rep- 

 resents the katabolism when standing quietly. 



Moreover, even with the limitations just indicated, the results 

 represent averages from which the energy expenditure of the 

 individual animal may differ considerably. Such averages are 

 useful as a basis for computing feed requirements and rations, 

 but it should be clearly understood that they are by no means 

 physiological constants which can be applied to all animals 



