Feeding Standards. 



241 



production in terms of starch have been calculated by Kellner. 

 No extended table will be given here. However, to make this 

 clear the digestible nutrients in a few common feeding materials 

 are brought together in the following table. This table includes 

 the amides, which are not, in American tables as a rule, dis- 

 tinctly separated, but included under the term "crude protein'* 

 (NX 6.25). 



Pounds of Digestible Matter in 1000 Pounds of Various Feeds. 



From these data the maintenance value in terms of starch is 

 made by the simple calculation: Protein X 1-25 1 + Amides X 

 0.6 + Fat X 2.3 + Garb. + Fiber. 



From this we see that the feeds for maintenance are valued at 

 the full heat value of the digestible constituents. The heat which 

 is the final outcome of the mechanical labor employed in digestion, 

 can serve for warming the animal. But when the productive 

 value is considered, it has been found that if we take only the 

 digestible fat, protein, and carbohydrates of the ration, and give 

 to each the energy value found for it in Kellner 's production ex- 

 periments, the sum of these will approximate the values actually 

 obtained in the experiments tried. Consequently the productive 

 value in terms of starch = Fat X 2.3 + Protein + Garb. 



l The factors 1.25, 6, and 2.3 are those in use in Europe for converting 

 the food constituents to an energy basis equivalent to starch. It should be 

 observed that generally the factor 2.4 for fat is the only one used. 



