THE FEEDING OF HORSES 233 



contained in the protoplasm of tlie cell, the unit of structure of 

 the animal body. 



The inorganic material of bone, to which its strength and 

 texture are due, is largely calcium phosphate, although other 

 mineral or ash constituents are present in other tissues of the 

 body. 



Protein is the chief source of the cell protoplasm and is the 

 most important tissue builder. 



The carbohydrates are fat formers and, in addition, furnish 

 the energy necessary to do" work, after the operation of the vital 

 functions and the maintenance of the body temperature have 

 been taken care of. 



Fat ser\^es the same purposes, but with a caloric or heat 

 value 2.25 times as great. 



Rations Not All Alike. — ^It is obvicms that mature animals 

 at work, at rest, pregnant mares, or growing colts require rations 

 made up of these compounds in different proportions. When the 

 proportions of the protein on the one hand and the carbohy- 

 drates plus the fats on the other are such as to just meet the 

 requirements of the horse in question, with no excess of either, 

 the ration is said to be halanced. The relation of the protein 

 to the carbohydrates plus fats is expressed as the nutritive ratio. 

 This is determined by adding to the digestible carbohydrates 

 contained in the ration, the fats multiplied by 2.25, then divid- 

 ing the sum by the amount of the protein. The protein is to the 

 carbohydrate as one is to the quotient. 



The ration is considered wide if the ratio of carbohydrates 

 plus fats is large Avhen compared with the protein. If the ratio 

 is small the ration is called narrow. 



There is no relation between the balance and the sufficiency 

 of the ration. A horse may stance on a perfectly balanced ration 

 of insufficient quantity, or he may be surfeited with feed and 

 yet suffer from malnutrition if the relative amounts of protein 

 and carbohydrates plus fats are not properly balanced. 



In view of the fact that maintenance requirements, which 

 amount to about 50 per cent of a full ration, Avill be satisfied 

 before anything is available to be turned to work, the full ration, 

 so far a^ quantity is concerned, is most productive. 



