270 The Feeding of Animals 



become, through the necessary processes of separation, 

 too costly to be considered for cattle -feeding purposes, 

 and their prices in these forms are not a proper 

 basis of calculation. If, therefore, a farmer pays $15 

 for a ton of wheat bran, what proportion of this sum 

 shall he assign to the 320 pounds of protein, the 

 1,240 pounds of carbohydrates, or the 84 pounds of 

 fats? 



Commercially considered our problem is complex, 

 and no simple process will solve it. If we were to 

 determine what is the cost of one pound of dry matter 

 through the simple division of the price of a ton of 

 feed by the pounds of dry matter which it contains, 

 and then declare that all forms of dry matter have 

 equal cost, we would get as many prices for protein 

 and starch as there are commercial feeds, with no dis- 

 tinction as to the money value of these nutrients. 

 Such a method would be absurd. It would be a bare 

 assumption to declare that all the compounds of a 

 food should have equal market cost. 



An attempt was made in Germany, and to some 

 extent in this country, to calculate by the "method of 

 least squares" what should be considered the cost of 

 protein, carbohydrates, and fats as based upon the 

 ton prices of a variety of feeding stuffs. Valuations 

 so derived appeared to find favor for a time, and some 

 of our experiment stations, following the lead of Ger- 

 man chemists, published pound prices for the three 

 classes of nutrients, and calculated what commercial 

 cattle foods should cost when valued on a common 

 basis. It was soon found, however, that, mathemati- 



