110 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



auother demand to be met by tbe food supply, and a proper regard to 

 the food necessary to supply this demand is of the greatest practical 

 imjiortauce to the farmer. 



Since the tissues of the body are mainly composed of nitrogenous and 

 phosphatic material, it is obvious that for the production of such tissues 

 in the young animal, and for the repair of their waste in the adult, only 

 food which is made up of such nitrogenous or phosphatic material will 

 suffice for such purpose ; but for the other functions of food, viz., the 

 supply of animal heat and muscular force, other kinds of food, those 

 rich in carbohydrates, will suffice, since it appears to be conclusively 

 established by exi^eriment, the results of which are universally accepted, 

 that animal heat and muscular force proceed from the combustion or 

 oxidation of food constituents in the blood. 



But these latter functions of food may be performed by the oxidation 

 of nitrogenous or phosphatic foods as well as by that of the carbohy- 

 drates, and such is found to be the case when through lack of sufficient 

 food, either partial or complete starvation, it is found that the animal 

 becomes emaciated, and, in fact, the functions of life are being performed 

 at the expense of the muscular tissues, after the reserve sui^plies of fat 

 in the body have become exhausted. 



True economy in feeding, therefore, demands that the proper propor- 

 tion of these three kinds of food be x>i"ovitled ; and since the carbohy- 

 drates are much cheaper than the other kinds, it is advisable that only 

 sufficient quantity of the other kinds be furnished for the fidl perform- 

 ance of those functions of which these only are capable, namely the sup- 

 ply of the tissues, since any other procedure would be extravagant and 

 wasteful. 



A judicious combination of fodders so as to produce this result, and a 

 utilization of the fodders in his i^ossession by mixture with others which 

 he may buy, so as to economize all the nutrients, is the problem which 

 should occupy the farmer to-day. 



It is in this direction that the chemist is able to furnish great assist- 

 ance to the stock-raiser, by analyses of fodder stuffs which shall show 

 him how to feed them economically, by calculating suitable rations of 

 various substances, by finding values to api^ly to the digestible i)ortions 

 of fodders in order to calculate their cost in the market, and by practi- 

 cal feeding experiments to show how we may interpret the results ob- 

 tained in the laboratory. 



THE CALCULATION OF FODDER VALUES. 



In the description of the analyses of grains, p. — , mention has been 

 made of the figures assigned by Wolf and Koeuig to the nutritive con- 

 stituents of the cereals for determining their values ; and the manner ol 

 deducing others, suitable to the American market, from the average 

 value of crops for the last ten years' has been explained. 



In the case of hay, the average value since 1870 has been $12.86 per 

 ton ; and this, taken in conjunction with the average composition of 

 American grasses analyzed by us, gives the following: 



Values of ihe mculalle nutrienis of Amincan hay. 



Albiimiuokls 3. 40 couts per pomul. 



Pats • 2.93 cents ijcr i)ouml. 



Nitrogen, free extract 72 cent per pound. 



These figures have been used in the calculation of the relative fodder 

 values given in cue of the last columns of the table. It will be seen 



