306 MASS. EXPERIMENT STATION BULLETIN 181. 



Table V. — Computation of Digestion Coefficients — Concluded. 



Series XXII., Sudan Grass (Green), Period 17 — Concluded. 



Sheep XIII. 



Discussion of the Results. 



Having presented in the foregoing pages a statement of the general 

 purpose of these experiments, an explanation of the tables, and the data 

 of the composition of the feeds and feces, as well as the detailed data 

 of the e.xperiments, including the computation of the digestion coefficients, 

 it is intended in the pages which follow to state briefly the general character 

 of each feed, summarize the coefficients secured, and draw such conclu- 

 sions as the results indicate. 



In noting the variations which occur when the same feed is fed to 

 different sheep, the fact must not be lost sight of that digestibility is 

 made up of a number of processes. Armsby states the matter clearly 

 when he says "digestibility in ruminants is a very complex affair, 

 depending on many factors; ... it may be characterized as a series of 

 fermentations effected in part by a variety of organized ferments, and 

 in part by enz5mies secreted by the digestive organs or contained in the 

 feed itself. Changes in the composition of the contents of the digestive 

 tract, or in the rapidity with which they move forward through it, can 

 hardly fail to influence in a variety of ways the course of these fermenta- 

 tions, and it seems, on the whole, rather surprising that they go forward 

 as rapidly as they do." 



