ENERGY-PRODUCTION VALUES 449 



As an illustration of the method of computation we 

 may take average timothy hay, containing the following 

 amounts of digestible matter: 



In 100 PotTNDS OF Timothy Hat 



Pounds 



Dry matter 88.4 



Digestible 



Protein 3. 



Carbohydrates 42.8 



Fat 1.2 



Total digestible organic matter 47. 



According to previous figures, each pound of digestible 

 organic matter in roughage contains approximately 1.588 

 Therms of metabolizable energy, while Table 1 shows 

 that each pound of dry matter of timothy hay causes a 

 heat expenditure of 0.3547 Therms. The net energy value, 

 therefore, of the 88.4 pounds of dry matter contained in 

 100 pounds of the hay would be : 



Metabolizable energy . . 1.588 Therms x 47.0=74.64 Therms 

 Heat expenditure 0.3547 Thennsx 88.4=31.36 Therms 



Net energy value 43.28 Therms 



Continuing, Armsby and Putney discuss the net energy 

 values of American feeding-stuffs as follows: 



"Henry and Morrison ('Feeds and Feeding,' 15th 

 edition, pages 633-66) have recently published a very 

 valuable compilation of American analyses of feeding- 

 stuffs and of the results of American digestion experi- 

 ments, and on this basis have calculated the content of 

 digestible nutrients (for ruminants) in a great variety of 

 feeding-stuffs. 



"With the permission of these authors, we have under- 

 taken to compute from their tables the net energy values 

 of the more important feeding-stuffs in the manner illus- 

 cc 



