1890.] PUBLIC DOCUMENT — No. 4. 109 



entirely out of account, and give our attention to the diges- 

 tible part. This we consider to be made up of two portions, 

 quite distinct in character and having different uses in the 

 system : one part keeps up the natural heat of the body, 

 and we call it the heat-producing part ; the other builds up 

 the system, makes the muscle or flesh, and is the chief 

 instrument in making these muscles or this flesh yield us 

 valuable productions, such as labor, speed, milk, butter, 

 wool, etc. We call this part the flesh-producing or the 

 force-producing part. It will be evident from these defini- 

 tions that the amounts of these two kinds of food required 

 by the animal will be determined by what the animal is 

 doing. A full-grown ox, that is neither gaining nor losing in 

 weight and is doing no work, has but little need of the 

 flesh or force producing parts of the food. It is only 

 existing, and needs to do but little more than keep up the 

 natural heat of the body. We find an animal under these 

 conditions to use principally the heat-producing parts of 

 the food. Yet even then the animal will need some of the 

 flesh or force producing part ; for in the mere act of living 

 the muscles are being continually worn out and need re- 

 placing, and all the actions of the heart, lungs, etc., require 

 some force, and this force can come only from the force- 

 producing part of the food. If, now, this ox is set to work, 

 at once there is a demand by its system for more muscle, 

 more flesh, more force. If we do not increase the amount 

 of the flesh-producing material in the food, the animal can- 

 not replace the w^orn-out flesh, and grows thin. All produc- 

 tion, whether of growth, labor, wool or milk, uses up flesh 

 in the animal ; and so we can use the v,'ordJIesh as including 

 all these productions of the animal. This single example 

 will serve to show the foundation of the principles of 

 rational stock-feeding. 



The animal has a certain work to do, this work will re- 

 quire the using up of a certain amount of heat and a certain 

 amount of flesh ; and w^e must supply in the food enough of 

 the heat-producing material to make up the heat, and enough 

 of the flesh-producing material to keep up the supply of flesh. 

 If the food just does this, Avith no surplus, it is exactly 

 suited to the case, and is said to be a well-balanced ration. 



