658 



EXPERIMENT STATION RECORD. 



of a- fermentation in which marsh gas is generated, and hence the full 

 fuel value of this cellulose is not realized in the body. 



It would follow from this that the so-called digestible cellulose has 

 less value than the digested nitrogen-free extract, but this is oul^^ true 

 provided the carbohydrates of the nitrogen-free extract do not undergo 

 a marsh-gas fermentation, or produce any methan. Some authors 

 ascribe to the digested cellulose very little or no value, while others 

 believe it to be fully equal to the digested nitrogeu-free extract. P. 

 Holdefleiss,' who has recently investigated the subject, calculates it 

 to have SO ])er cent of the vahie of nitrogen-free extract. 



Ul) to the present time it has not been shown that methan, or marsh 

 gas, comes entirely from the digested cellulose. On the contrary, it is 

 very probable that methan also results from decomposed starch, etc., 

 of the feeding stuff, and in this case the decrease in fuel value due to 

 methan formation, mentioned above, would apply equally as well to 

 the nitrogen-free extract as to the digested cellulose. 



The conclusion appears to the writer to be warranted that the 

 digested crude liber and the digested nitrogen-free extract are not only 

 of similar, but in ail respects equivalent, value in nutrition. Certainly 

 not all of the crude fil)er eaten by animals is recovered in the excre- 

 ment. Of the 40.93 per cent of crude fiber in wheat meal 52 per cent 

 is digested by cattle, according to llenneberg and Stohmann,^ i. e., 

 the meal contains 24 per cent of digestible crude fiber; and of the 42.96 

 per cent of crude fiber in oat straw 50 per cent is digested by sheep, 

 equivalent to 21.48 per cent of digestible fiber in the straw.' Other 

 data are as follows : 



Digestibility of crude fiher. 



jCrnde liber 

 I content. 



Bean straw 



Oats a 



Oats 



Corn meal 6 

 Corn menlc 



Per cent. 



41.67 



12.07 



12.07 



1.75 



2.15 



Animal 

 used. 



Sbeep. 

 Horse. 

 Sheep. 

 Do. 

 Horse. 



a Dietrich and Kiinig, loc. cit., p. 1108. 



h Wolff, Funkc, Kreuzhage, and Kelluer, Limdw. Jabib., 8 (1879), Sup. I, pp. 96, 97. 



« Dietrich and Konig, loc. cit. p. 1109. 



It appears that quite a large part of the crude fiber is digested, and 



hence the assumption that the portion of a feeding stuff insoluble in 



1.25 percent sulphuric acid and 1.25 per cent potassium hydroxid is not 



dissolved in the body of the animal is incorrect. 



, 



' Landw. Inst. Halle, Bericlite 12, pp. 52, 98. 



- Weender Beitriige, vol. 2, p. 23; Dietrich and Kunis?, Zusaniiiiensetzung imd 

 Yerdaulichkeit der Fnttermittel, part 2, p. 1097. 



3 Hofmeister, Landw. Vers. Stat. 10 (1868), p. 295; Dietrich ;iud Konig, loc cit., 

 p. 1098. 



