DIGESTION AND RESORPTION 



These figures, together with the weights of hay eaten and feces 

 excreted per day, yield the following results : 



TABLE 20. RESULTS OF A DIGESTION EXPERIMENT 



161. Digestibility of concentrates. The method just outlined 

 for determining the digestibility of a roughage or of a total ration 

 is in conception very simple. The determination of the digestibility 

 of concentrates by herbivora is somewhat more complicated, since 

 they cannot be made the sole feed of these animals. They must, 

 therefore, be fed along with a known amount of a roughage whose 

 digestibility by the same animal is likewise determined in a preced- 

 ing or following period. From the digestibility of the total ration 

 and the known digestibility of the roughage that of the concentrate 

 is obtained by means of a second calculation by difference. 



Thus, the same steer used in the experiment of the preceding para- 

 graph received per day in a subsequent period the same amount, 3.7 

 kilograms, of clover hay and in addition 4 kilograms of maize meal. 

 The average daily excretion of feces on this mixed ration was 8.715 

 kilograms. An analysis of the clover hay used in this period showed 

 but slight variations from that of the preceding period. The com- 

 position of the maize meal and of the feces was : 



Water 



Ash 



Protein .... 

 Non-protein . . . 

 Crude fiber . . . 

 Nitrogen-free extract 

 Ether extract 



FECES 

 % 



81.91 

 1.77 

 3.66 



6.51 

 5-71 

 0.44 



