MEASURING THE USEFULNESS OF FEEDS 



39 



than do horses and swine. (85) In spite of this difference, the coeffi- 

 cients of digestibility obtained with ruminants are commonly used in 

 computing rations for horses and swine as well, for but few digestion 

 trials have been carried on with the latter animals. However, no error 

 of consequence is involved in this, for the recommendations in modern 

 feeding standards are designed to meet these conditions. 



Individual animals of the same species vary somewhat in their ability 

 to digest the same feeds. For this reason, it is essential, when com- 

 puting the digestible nutrients in feeds as a basis for balancing rations 

 for live stock, to use average coefficients of digestibility, based on all 

 representative digestion trials which have been conducted. The authors 

 have therefore compiled and averaged the coefficients for the various 

 feeding stuffs, as determined in the many trials by the experiment 

 stations. These average coefficients of digestibility are presented in Ap- 

 pendix Table II. In the case of feeds for which American data are 

 not available, coefficients from European sources have been included. 

 From this extensive table the following examples are taken to show 

 the digestibility of typical feeds : 



Coefficients of digestibility of typical feeding stuffs, from Appendix 



Table II 



The table shows that $or dent corn 90 per ct. of the total dry matter, 

 74 per ct. of the crude protein, 57 per ct. of the fiber, 94 per ct. of the 

 nitrogen-free extract, and 93 per ct. of the fat are digestible. Feeds 

 which contain little fiber, such as corn and wheat, show high digestibility, 

 because their nutrients are not protected from the action of the digestive 

 juices by thick cell walls of cellulose, or fiber. Owing to their larger fiber 

 content, oats and wheat bran are less digestible than corn or wheat. As 



