PRINCIPLES OF FEEDING. 139 



ether extract .3, and the carbohydrates 10., how much 

 protein does it contain ? 



(c] If the nutritive ratio of a food is i: 5.2, the protein 

 2.8, and the ether extract .8, how much carbohydrate 

 does it contain ? 



4. Wide and Narrow Ratios. When the 

 amount of carbohydrate and ether extract is 

 large in proportion to the amount of protein, 

 the ratio is called wide. For example, the nu- 

 tritive ratio of corn stover is i : 20, and that of 

 oat straw 1:33.7. Both of these would be called 

 wide ratios. When the amount of heat-produ- 

 cing elements is small in proportion to the 

 amount of protein, the ratio is said to be nar- 

 row, as in oil meal, where it is i: 1.7. 



In Indian corn the ratio is 1:9.8, and is called 

 medium. As is shown by the table, a medium 

 ratio most often gives the best result, growing 

 and heavily worked animals (as young cattle, 

 1:4.5, an d heavily worked horses, 1:6) requir- 

 ing a narrower ration that is, containing a 

 greater proportion of protein to carbohydrates 

 than the mature animal, or animal, or those 

 doing light work (as, 18:24 months old dairy 

 cattle, 1:8.5, a d a horse doing light work, 1:7). 

 This is due to the fact that protein is needed in 

 the growing and working animal for the up- 

 building of tissues. 



It will be noticed that there is no wide nutri- 

 tive ratio given in the table, as in that case the 



