250 



MxVKUAL OF CATTLE-FEEDING. 



not digested, or is at least, even if present in an easily- 

 soluble form, not resorbed, bnt excreted with the dung. 



Compensation. — It is a noteworthy fact that a coqu- 

 peiisatlon takes place between the digested portion of the 

 crude fibre and the undigested portion of the nitrogen-free 

 extract. That is to say, these two quantities are always 

 nearly equal, so that the amount of the nitrogen-free ex- 

 tract found by analysis is an a])^roximate measure of the di- 

 gestibility of the total non-nitrogenous matters of the fodder^ 

 exclusive offat^ {Le,, crude fibre -f- nitrogen-free extract). 



Tliis fact, however, is only true in a general way and on 

 the average. In particular cases considerable variations 

 are not infrequent, so that the quantity of non-nitrogenous 

 substance digested varies from sometimes 120 per cent, to 

 as low as 80 per cent, or even less, of the amount of 

 nitrogen-free extract found by analysis, the theoretical 

 number being, of course, 100 per cent. 



It has been observed in several cases that the exactness 

 of the compensation between the digested cinide fibre and 

 the itudigested extract is influenced by the digestibility of 

 the crude fibre. 



Thus Stohmann,t who was the first to call attention to 

 this fact, obtained in experiments on goats, the following 

 figures for meadow hay : 



Hay 



No. 3. 



(Another 



animal.) 



Digestible fibre and extract in per 

 cent of mtrogen-free extract. . . 



Digrestibility of crude fibre. 



Hay 

 No. 1. 



Hay 



No. 2. 



Hay 

 No. 3. 



97 



86 



82 



63 6 



58.0 



51.0 



73 

 44 6 



* The fat is sometimes included. Its amount is so small as to make 

 little difference practically 



f **Biologisclie Studien," 1 Heft, p. 73. 



