326 AGRICULTURAL CHEMISTRY 



a number of days, a weighed amount of food which is 

 analyzed. All of the feces or solid excrements produced 

 during the experimental period are collected, weighed 

 and analyzed. After undergoing the process of digestion, 

 the undigested portions of the food along with a small 

 amount of digested products are excreted as feces, while 

 the liquid wastes of the body contain the products of the 

 digested food. From the weight of the food consumed 

 and its analysis, the amount of each class of nutrients con- 

 sumed is determined. From the dry matter of the feces, 

 the undigested nutrients are likewise determined. The 

 undigested nutrients subtracted from the total nutrients 

 in the food consumed give the amounts digested which 

 are calculated on a percentage basis. In the case of clover 

 hay, an animal may consume 28 pounds per day containing 

 12 per cent, protein ; this is equivalent to 3.36 pounds of 

 protein (28 X 0.12 = 3.36). An account is opened with 

 the animal in which a charge for 3.3 pounds of protein is 

 entered. From the 28 pounds of food, 40 pounds of feces 

 or excrements are obtained, as a large amount of water 

 is added during the process of digestion. The feces 

 which are composed largely of the indigestible portions 

 of the food are analyzed and found to contain 20 per cent, 

 of dry matter; this is equivalent to 8 pounds of indigesti- 

 ble matter yielded by the 28 pounds of clover (40 X 0.20 

 = 8). The dry matter is analyzed and found to contain 

 15 per cent, of protein ; this is equivalent to 1.2 pounds 

 of protein (8 X 0.15 = 1.2). The animal was charged 

 with 3.36 pounds of total protein ; 1.2 pounds are found 

 to be indigestible, leaving a balance of 2.16 pounds of 



