30 



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 com- 

 pounds whose composition corresponds very closely to similar 

 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 ferments of the body 

 upon the plant constituents, and now know that the digestive pro- 

 teins, fats and carbohydrates of plant origin are used in the 

 animal body 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 composi- 

 tion of animal and plant tissue and their products, the processes 

 of digestion, assimilation, etc., one might surmise that it would 

 be possible to compound a food ration which should supply all the 

 various elements in the proper proportion necessary for the complete 

 nourishment of the different 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 difference 

 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 particular 

 direction we must so treat our animals that perfect health shall be 

 maintained. This is where knowledge obtained by practical ex- 

 perience applies, and in this part of the subject we are particularly 

 interested. The study of the scientific investigations of questions 

 relating to feeds and feeding is interesting and profitable. The 

 reader is referred to various books and agricultural experiment 

 station bulletins for information concerning it. Unfortunately, 

 there is a scarcity of literature upon the subject of the hygiene of 

 feeding. What information we possess has been gained largely 



