DIGESTIBILITY 



25 



amounts represents the amount digested. From these data 

 it is easy to determine the percentage of digestible nutrients 

 in a feeding stuff. The relative values of feeds may be 

 found by comparing the amounts of digestible nutrients 

 which they contain as shown by the tables in the Appendix. 

 Factors Influencing Digestibility. — There are many 

 factors which influence the digestibihty of feeds. The most 

 common of these are : 



1. The relative amounts of the different nutrients. Feeds 

 high in crude fiber and low in nitrogen free extract, such as 

 coarse fodders, are low in digestibility, while those low in 

 crude fiber and high in nitrogen free extract, such as con- 

 centrates, are high in digestibility. 



2. The maturity of the plant. The stage of maturity has 

 an effect upon the digestibility of roughages. The younger 

 the plant, the higher the digestibility. This is due in a 

 measure to the fact that as the plant advances in age, the 

 crude fiber becomes more woody and harder for the diges- 

 tive juices to dissolve. But the amounts of starch and sugar 

 also increase, so that the total amounts of digestible material 

 increase as the plant approaches maturity. 



Fig. 6. — Grinding and cutting machines used to increase digestibility of feeds. 



