DIGESTION AND NUTRITION 341 



there is a large amount of nitrogen-free extract compounds 

 (starch) , and in the table it will be observed that they are 

 more completely digested than the crude protein which is 

 present in small amounts. Whenever a food contains 

 nutrients in small amounts they are in dilute forms, and 

 are not as completely extracted as when present in larger 

 amounts. The coarse fodders are not as completely di- 

 gested as the grains and milled products. In the coarse 

 fodders, the digestion coefficients range from 30 to 65, 

 while in grains and milled products, the same nutrient 

 ranges in digestibility from 70 to 95. 



466. Digestible Nutrients of Foods. When the total 

 amounts of nutrients in a food are multiplied by the 

 digestion coefficients, the available nutrients are secured. 

 For example, clover hay contains 12 per cent, crude pro- 

 tein which is 60 per cent, digestible. The available or 

 digestible crude protein of the clover hay is 7.2 (12 X 

 0.6 = 7.2). In like manner, all of the digestible nutri- 

 ents of foods are ascertained. The total amount of each 

 nutrient is^multiplied by its digestion coefficient, which 

 gives the total available or digestible nutrients. When 

 the average composition of American feeding stuffs and 

 the average digestion coefficients are used, the average 

 digestible or available nutrients are obtained. Such a 

 table is given at the end of the chapter. In the use of 

 this table, it should be remembered that the figures apply 

 simply to average conditions, and are susceptible to any 

 of the influences which affect either the composition or 

 the digestibility of foods, and while the amounts of 

 nutrients given are fairly constant, they nevertheless 



