73 



the basis for ration calculations. Fat, it has been determined, is 

 worth about 2 times as much as carbohydrates pound for pound. 



Protein. Protein (or nitrogenotus material) is that constituent 

 of the plant containing nitrogen. It is sometimes called the 'flesh 

 former.' It enters into the composition of most parts of the animal 

 body and is a most important constituent of milk. No other sub- 

 stance can take its place. It is believed, however, that protein may 

 take the place of, or can be converted into, fat. It is thus evident 

 that protein is an indispensable part of every ration. 



Fat. Fat is the part of a feeding stuff that may be dissolved 

 from it by ether. Real fats, moreover, include wax and some other 

 constituents of plants. Fat in the food may be stored in the body 

 as fat, used to maintain the heat of the body or converted into the 

 fat of milk. As already stated, one pound of fat is worth about 2J 

 pounds of carbohydrates for heat production. 



Asli. Ash is what is left after the combustible part of a feeding 

 stuff is burned away. It is used in the formation of bone and the 

 elaboration of the digestive juices. 



Water is the most common and the most important substance 

 in the body. It serves as a solvent for most solids in the body and 

 enters largely into the composition of every part of it as well as 

 plays a most important part in all functions. 



Mineral matter enters more or less into the composition of the 

 muscles and other soft tissues, but is used most largely in building 

 nip bone. 



Fat is found in greater or less quantities in most tissues while 

 protein enters into the composition of practically every part of the 

 animal body or product. Milk, with the production of which we are 

 especially concerned, hns protein for about one-third of its dry 

 matter content, and fat for another third thereof, while sugar, 

 etc., make up the rest. 



PROPORTIONS IN WHICH DIFFERENT FOOD CONSTITUENTS SHOULD BE FED TO 



DAIRY COWS. 



A great deal of work has been done by investigators to determine 

 just how much of each of these food constituents is needed by animals 

 under given conditions. It is a general principle that an animal 

 should have as much water as its body calls for, and sufficient ash 

 seems to be fed in ordinary rations to meet all demands. It 



