256 BOARD OF AGRICULTURE. [Pub. Doc. 



tissues, while non-nitrogenous substances exist largely as 

 fats. Of the inorganic constituents Ave have the various salts 

 which, taken collectively, form the ash. The salts consist of 

 lime, potash, soda, magnesia, etc. 



A chemical analysis of plants shows that we have in them 

 compounds whose composition corresponds very closely to 

 similiar substances found in the animal body. We find that 

 there are in plants both organic and inorganic compounds ; 

 protein, fats and carbohydrates belong to the former, the 

 various salts to the latter. 



Through our study of animal physiology and chemistry 

 we have learned of the action of the various digestive fer- 

 ments of the body upon the plant constitutents, and now 

 know that the digestive proteins, fats and carbohydrates of 

 plant origin are used in the animal l)ody for the production 

 of muscle, bone, milk, heat, energy, etc. 



In consideration of what has been learned by experimental 

 research in physiology and allied sciences regarding the com- 

 position of animal and plant tissue and their products, the 

 processes of digestion, assimilation, etc., one might surmise 

 that it would l)e possible to compound a concentrated food 

 ration which should supply all the various elements in the 

 proper proportion necessary for the complete nourishment 

 of the difierent tissues of the animal body. Such, however, 

 is not the case. In order to keep the animal organism in a 

 normal, healthful condition, we need to supply more than 

 what is shown to exist by chemical analysis in the various 

 tissues. A certain mechanical condition of the food is 

 requisite, as well as a sufficiency of bulk. The digestibility 

 of the food, the quality, etc., have to be taken into account, 

 and we must not forget that anatomical variations have their 

 influence in connection with proper feeding. In other words, 

 to obtain certain results in the feeding of farm animals, we 

 must bring into play the sum total of our knowledge of the 

 chemistry and physiology of feeding, together with those 

 practical points learned by experience. This applies in the 

 case of all farm animals, it makes no difierence whether we 

 feed for growth, milk, beef, pork, mutton, or, as in the 

 horse, for force and energy. In any case we have to bear in 

 mind that in order to secure the best results in any particu- 



