28 

 APPENDIX. 



As stated in the introduction, the tables giving the percentage com- 

 position of the foods analysed furnish us with information regarding the 

 total amounts of the different constituents present in foods, but as only 

 that portion of the food which is digested is of direct use to the animal, 

 it has been deemed advisable to append a table giving the approximate 

 amounts of digestible nutrients contained in the various fodders. The 

 data upon which some of these calculations are based are taken from the 

 results reported in Bulletin No. 'j'j of the U. S. Department of Agricul- 

 ture. The digestibility of a number of these feeding-stuffs under con- 

 sideration has been determined at this Station, and in such cases we 

 have used our own data in calculating the amounts of digestible nutrients. 



As will be seen from the following table, the digestibility of the dif- 

 ferent foods varies markedly, and it must also be remembered that the 

 digestibility of some foods varies under different conditions. Further- 

 more, in those foods which are marked thus * the digestibile compon- 

 ents have been calculated from the digestibility of American feeding stuffs 

 of the same name, and the digestion co-eflficients of these may vary quite 

 widely from our own. Therefore, when using the figures which are 

 given in the following table, the feeder must bear in mind that he is deal- 

 ing with approximate quantities only. 



The importance of the supply of protein in a ration has been suf- 

 ficiently emphasized to require no further mention. It may be stated, 

 however, that if an excess of the amount required to build up and repair 

 the waste of the body be fed the protein may be converted into fat and 

 deposited as such or used to produce heat and energy. For these pur- 

 poses it is about as efficient as the carbohydrates, but it is far more ex- 

 pensive than the latter, and, therefore, only as much should be supplied 

 to the mature animal as will be used in repairing the necessary breaking 

 down of the nitrogenous tissues in the animal body. In the case of 

 growing animals and such animals as are kept for the production of 

 milk, wool, and so forth, an increased amount of protein in the food is 

 necessary. 



The matter of computing rations for the various kinds of animals 

 raised on the farm is, therefore, an important one to the feeder, for 

 since the protein, on the one hand, and the carbohydrates on the other, 

 serve in the main different purposes in the animal economy, it is evident 

 that relative amounts of these nutrients in the food sJiould be considered. 

 This relation is called the nutritive ratio, which means simply the 

 relation of the digestible protein to the digestible carbohydrates and fat, 

 the fat having been multiplied by 2.25 before adding it to the carbohy- 

 drates The nutritive ratio is then found by dividing the carbohydrates 

 plus 2.25 times the fat by the protein. In the following table the sum of 

 the carbohydrates and fat thus obtained is given in the third column, which 

 divided by the protein, as given in the second column, gives us the nutri- 

 tive ratio of the food. 



