THE PRODUCTION VALUES OF FEEDING STUFFS 673 



Kellner's starch values yield numbers of the same order of 

 magnitude as those already familiar in tables of digestible nu- 

 trients and avoid unfamiliar units. They accomplish these 

 ends, however, by ignoring the whole conception on which the 

 system is built up, while some striking instances in recent lit- 

 erature have shown that it is not always easy, even for ex- 

 perts, to avoid confusion of thought in connection with their 

 use. It appears to the writer to have been an unfortunate con- 

 cession to attempt to express quantities of energy in terms of 

 matter. He believes the intelligent feeder can readily learn 

 to use units of energy in his computation of rations, as not a 

 few have already done, and that there are manifest advantages 

 in going over frankly and boldly to a system based on energy, 

 while the objection to the use of large numbers is readily avoided 

 by the employment of a larger unit of energy, the Therm (308). 

 Net energy values expressed in Therms per 100 pounds are of 

 the same order of magnitude as the familiar figures for di- 

 gestible nutrients, and even if 100 kilograms be made the 

 basis of calculation they are not inconveniently large. For 

 these reasons, energy values of feeding stuffs in the present 

 volume are expressed in Therms per 100 pounds. 



Computation from digestible organic matter 



773. Independent of chemical composition. It is apparent 

 from the foregoing description of Kellner's somewhat compli- 

 cated method that it is essentially based on the digestible 

 protein, carbohydrates and fats of the older relative values 

 (705-710), while it involves in its execution certain more or 

 less empirical corrections which are at bottom simply methods 

 of applying the average net results on typical feeding stuffs 

 to other materials. Armsby and Fries x have proposed a 

 method which seeks to attain the same end more directly and 

 simply, relating the energy content and the necessary deduc- 

 tions to the total dry matter or total digestible matter of the 

 feeding stuff independently of its chemical composition. 



The energy content of a feeding stuff is just as definite a 

 quantity as its content of protein, carbohydrates, or fats, and 



1 Jour. Agr. Research, 3 (1915), 486. 

 2 X 



