RATION OF THE YOUNG ANIMAL 69 



amount of digestible protein. The quotient derived will 

 be the second term of the ratio of which the first term is i. 

 For example, dent corn contains 7.8 pounds of di- 

 gestible protein, 66.8 pounds of digestible carbohydrates, 

 and 4.3 pounds of digestible fat in each 100 pounds. The 

 nutritive ratio of dent corn is found in the following way : 



— ^i-^t — ^ = 0.8. The nutritive ratio of corn is then 



7.8 ^ 



said to be I : 9.8. 



Rations that are relatively rich in protein are called 

 narrow rations and those that are poor in protein are called 

 wide rations. Cottonseed meal has the narrow nutritive 

 ratio of i : 1.14; rye straw has the wide ratio of i : 57.8; 

 and oats has the medium nutritive ratio of i : 5.49. 



How Rations should Vary. — Youth is the period of the 

 animal's life when normal development and growth take 

 place. To secure the maximum growth the ration of the 

 young animal should supply sufficient quantities of protein 

 and mineral matter. 



The mature animal does not need such a high propor- 

 tion of protein and mineral matter in its ration, because 

 growth is complete. Sufficient protein to repair waste is 

 all that is essential. Because carbohydrate and fat ma- 

 terials are cheaper than are protein and mineral matter, 

 it is more economical to feed the mature animal a wider 

 ration than that fed to the young animal. 



The Needs of the Young Animal. — In the corn belt 

 young animals are often raised to maturity on rations de- 

 ficient in protein and mineral matter. Young pigs suffer 

 most from this lack. The rations of calves usually con- 

 tain roughage materials higher in mineral content. Lime 

 and phosphorus are the mineral constituents needed in 



