FEEDS AND FEEDING. 329 



Experiments have demonstrated the fact that the protein con- 

 tent of corn varies greatly in the same type and even in the same 

 field. 



The Illinois Experiment Station has conclusively proven that 

 by proper selection we can increase the protein content. 



The Ohio Experiment Station has shown by chemical anal- 

 ysis that the kernels from one ear of corn tested 8.34 per cent 

 protein, while the kernels from another ear from the same va- 

 riety and crib, tested 13.14 per cent protein. 



This accounts for the variation in the different tables that 

 have been prepared by chemists showing the composition of 

 food materials; hence in the preparation of a table for feeding 

 purposes we must get the average composition. In the crib 

 above mentioned the average run of corn tested 9.97 per cent 

 protein. 



Composition of Food and Digestive Nutrients Compared. 



A chemical analysis of 100 pounds of corn according to cer- 

 tain authorities is 10.6 pounds of water, 10.3 pounds of protein, 

 72.6 pounds of carbohydrates, 5.0 pounds of fat, 1.5 pounds of 

 ash. 



These food materials are not all taken up by the body. The 

 amount of the same kind of food digested and assimilated varies 

 in different kinds of animals, and even among animals of the 

 same kind. 



It has been demonstrated that the per cent of digestible 

 nutrients in corn is as follows : 76 per cent of the protein, 66.7 

 per cent of the carbohydrates, 86 per cent of the fat. The num- 

 ber expressing the percentage digestible is called the digestion 

 coefficient. 



PROBLEMS. 



1. How many pounds of each of the following digestible nutrients 

 are there in 100 pounds of corn; digestible protein, digestible carbohy- 

 drates, digestible fat? 



2. How many pounds of water and how many pounds of dry matter 

 in 100 pounds of corn? 



In some tables showing the digestible nutrients in 100 pounds 

 of feed, the per cent of fat and carbohydrates are added together. 



