350 FEEDING WITH SUGAR BEETS, SUGAR, ETC. 



There are numerous theories attempting to prove that cellulose undergoes a 

 partial fermentation in the intestinal canal, during which period there is the 

 generation of marsh gas. One fact is certain, and numerous figures could be 

 given proving such to be the case it is mainly pure cellulose that is digested 

 and only a small portion of the crude cellulose. Any theory respecting trans- 

 formation of cellulose during passage through the intestinal canal would apply 

 to other fodders that are difficult of assimilation. 



The digestibility of cellulose may be calculated by the Wolff formula; 



Digestibility of C. = Crude fibre 



Protein -f- fat and nitrogen-free extract 

 Some recommend the Mehlin formula: 



Digestibility of C. = $ X Fat + nitrogen-free extract - protein 



Crude fibre. 



The results obtained by estimating with these two formulae are not the same. 



A part of the nitrogen-free extract of a fodder may be considered indigest- 

 ible and is thrown out in the excrements. 



Mehlin says that the coefficient of digestibility of nitrogen-free extract may 

 be calculated by the formula: 



Digestibility of nitrogen-free extract = 2 Protein + Lign in 



3 Crude fibre. 



As a general thing starch and sugar may be considered digestible; notwith- 

 standing this fact however, a certain amount of them is found in the excre- 

 ments when fed in excess. 



It is maintained that there is a sort of compensation between the crude cel- 

 lulose that is digested and the nitrogen-free extract that escapes digestion; 

 consequently it is admitted that the amount of nitrogen-free extract found in 

 the excrement represents the digested crude fibre and nitrogen-free extract, or 

 in other words, the digested non-nitrogenous matter exclusive of fat. 



The results obtained in this direction are very misleading, as it frequently 

 happens that the nitrogen-free extract in the dung is higher than could be 

 theoretically possible. 



The sum of digested nitrogen-free extract and crude fibre is equal to the 

 total nitrogen-free extract and fat. 



