1891.] PUBLIC DOCUMENT — No. 33. 143 



to select among the suitable fodder articles those which 

 furnish the required quantity and proportion of the three 

 essential food constituents in digestible form at the lowest 

 cost. For more details regarding this point, I have to refer 

 to previous annual reports. 



Assuming a similar degree of adaptation of the various 

 fodder articles offered for our choice, the question of cost 

 deserves a serious consideration, when feeding for profit. 

 The actual cost of a fodder article does not depend merely 

 upon its market price, but is materially affected by the value 

 of the manurial refuse it leaves behind, when it has served 

 its purpose as food. The higher the percentage of nitrogen, 

 phosphoric acid and potash a diet contains, the more valuable 

 is the manure it furnishes, under otherwise corresponding 

 circumstances. An excess, therefore, of any one or of all 

 three in one diet, as compared with that of another, counts 

 in favor of that particular diet, as far as the net cost of feed 

 is concerned ; for it is admissible, for mere practical 

 economical purposes, to assume that, in raising one and the 

 same kind of animals to a corresponding weight, or feeding 

 them for the same purpose, a corresponding amount of 

 nitrogen, phosphoric acid, potassium oxide, etc., will be 

 retained, and, according to circumstances, either stored up 

 in the growing animal, or pass into the milk, etc. The 

 commercial value of the three above-mentioned essential 

 articles of plant food, contained in the manure secured in 

 connection with our feeding experiments with milch cows, 

 has differed in case of different diets from less than one-third 

 to more than one-half of the market cost of feed consumed. 

 A few tabular statements may not be without interest on 

 this occasion ; for further illustration, I refer to our seventh 

 annual report, — 1889. 



1. Table showing the relative manurial value of stated 

 fodder. Net cost signifies market cost, less manurial value. 



2. Tables designed to show the approximate relative 

 cost per pound of digestible nitrogenous matter of some 

 prominent fodder articles. The calculation assumes in 

 every case a value of nine-tenths cents per pound of 

 digestible non-nitrogenous extract matter, and four and one- 

 third cents for digestible crude fat. The difference between 



