378 CATTLE-BREEDING. 



ble. When this additional factor is brought in 

 the question is fairly open and the things to be 

 determined are, first: The kind of food that is 

 needed to make the kind of growth demanded; 

 second, the kind of plant or grain which 

 offers that food; and third, the digestibility, or, 

 as it is called, the nutritive ratio of the given 

 plant. The cereal grains, the seeds such as 

 linseed,, cottonseed, etc. rich in oils are spe- 

 cially valuable for pressing forward flesh-mak- 

 ing, because they are composed of the elements 

 used in that process. 



An animal may pine and die for want of food 

 when heavily fed, if the food is not of the 

 right character. Thus sugar is highly nutri- 

 tious, but an animal could not subsist upon it for 

 any extended period. What is mainly needed 

 are those elements rich in nitrogen, called in 

 general albuminoids, whose function is muscle- 

 making. All the grains are rich in these mate- 

 rials. After them come certain nutrients, non- 

 nitrogenous in their composition, and called 

 carbo-hydrates because they are made up of 

 carbon and hydrogen and oxygen and the lat- 

 ter two elements in such proportion as to form 

 water. The stalks of plants, etc., largely con- 

 sist of these non-nitrogenous matters. 



So well has nature distributed these food 

 supplies that often a single plant furnishes an 

 entirely sufficient ration. Thus corn and corn- 



