210 STORRS AGRICULTURAL EXPERIMENT STATION. 
as determined by either natural or artificial digestion, should be 
taken as the basis of the calculation, they might be very far from 
expressing the nutritive value of the materials as they are actually 
utilized by the animal, because of the defects in our present 
methods of analysis and of classification of the nutrients. 
‘Finally, economical feeding is not simply a matter of fitting 
the nutrients of the food to the physiological demands, but of 
adjusting the kinds and quantities of feeding stuffs to their cost 
and to the amount and market value of the product. 
‘Prof. Kiihn’s conclusion is that to calculate rations upon a 
basis of the feeding standards and the average composition of 
the feeding stuffs, is irrational and may be very unprofitable. 
He would, however, by no means give up either standards or 
tables of composition. As regards the quantities of nutrients to 
be fed, he would take into consideration the individual needs 
of each animal and make the quantities of total food and of 
the several nutrients such as will best fit the special demands of 
the animal for sustenance and production. In calculating the 
amounts of feeding stuffs to be used he would not simply use the 
average figures, but would consider the ranges of variation and 
the composition of the particular materials to be fed. The ideal 
method would be to analyze the feeding stuffs in each case, if 
this were practicable, but it usually is not. But along with the 
chemistry and physiology of the subject, the skill of the experi- 
enced practical feeder is absolutely essential. For the method 
of ‘individual feeding’ which Prof. Kiihn recommends he gives 
suggestions of no little interest. 
“One matter which Prof. Kiihn rightly insists upon is the dis- 
tinction between the digestible protein, z. ¢., total digestible nitro- 
genous substances and the digestible actual albuminoids. He 
also urges with justice that the ether extract of the coarse fodders 
has a much lower feeding value than that of the concentrated 
fodders like oil cakes and meals, which consist mostly of the 
true fats. He insists with like good reason that what we call 
non-nitrogenous extract represents a great variety of materials 
unknown or of doubtful value. 
‘“Chemists clearly apprehend the difficulty with their analysis 
as measures of the nutritive value of feeding stuffs, but the 
experimenters and writers have not always appreciated the full 
import of the differences in individuality of animals, nor has 
the importance of taking into account the condition of the 

