1892.] PUBLIC DOCUMENT— No. 33. 91 



logical value of fat, — one of the non-nitrogenous con- 

 stituents, — two and one-half times as much as starch, 

 sugar, and other representatives of that group, its amount is 

 separately recorded. The same course, for similar reasons, 

 has of late been adopted with reference to certain forms of 

 nitrogenous organic constituents of fodder articles. 



Fatty substances include all the various natural fats of the 

 plant. Most plants contain more than was assumed at an 

 earlier stage of inquiry. As the fat is separated by means 

 of ether, the statements in the analyses do not exactly ex- 

 press the amount of fatty matter alone, but include more or 

 less resinous substances, wax, etc., which are largely soluble 

 in ether, and of a similar highly carbonaceous character. 

 The fat of the fodder seems to serve, in case of judicious 

 fodder rations, mainly to increase the stock of fat in the 

 animal which consumes the fodder. 



Digestibility of Fodder. — Wherever the article has been 

 tested by actual feeding experiment under skilful observa- 

 tion, the amount of each essential group of food constituents 

 which has been shown to be digestible is reported in connec- 

 tion with the chemical analysis, under the heading Digestible 

 Portion, per hundred weight or per ton. The higher or lower 

 degree of digestibility of a fodder article exerts a decided 

 influence on its nutritive value. Different stages of growth 

 affect the rates of digestibility of the various plant constitu- 

 ents. The same feature is noticed in regard to different 

 parts of plants, as well as in case of different kinds of 

 animals. 



More than two hundred fodder articles have thus far been 

 studied under varying circumstances, and most of our cur- 

 rent kinds of fodders have been tested in Europe and else- 

 where, in numerous well-conducted feeding experiments 

 with a suitable selection of different kinds of farm live-stock. 

 This fact imparts to many of the results recorded a sufficient 

 importance to recommend them as a basis of new feeding 

 trials, with feed stuffs raised in our climate, or obtained in 

 our home industries. 



Nutritive Ratio. — The last, but not least important, 

 column of the statement of the chemical analysis — quite 



