FOODS ANIMAL PRODUCTION. 



667 



Fiber, cellulose, and pentosans digested by a horse and sheeji 



Organic matter 



Pentosans 



Crude fiber 



Cellulose 



Experiment with a sheep. 



Experiment with a horse. 



In the 

 hay con- 

 sumed. 



Gm. 



795 

 171 



288 

 260 



In the ' Coefficient 

 feces ex- ; of digesti- ' 

 creted. , bility. I 



In the hay 

 consumed. 



am. 



281 



65 



105 



74 



Per ct. 

 64 

 62.6 

 65 

 71.5 



Gm. 

 6, 263 

 1,005 

 1, 938. 2 

 1,760 



In the 

 feces ex- 

 creted. 



Gm. 

 3,042 

 670 

 1, 306. 5 



862 



Coefficient 

 of digesti- 

 bility. 



In the case of the sheep the digestibilit}- of the fiber corresponds to 

 the mean value given by Woltl' for sheep. The digestibility of the 

 pure cellulose is greater than that of the fiber. The digestibility of 

 the pentosans, on the contrary, is not only lower than that of cellulose 

 and fiber, but is somewhat lower than that of the total organic matter. 

 This is still more marked with the horse. 



Considering the ratio between the cellulose and the pentosans as 

 found in the experiment with sheep, it is shown that the ratio in the 

 hay is first altered in the third stomach. This may be due to the fact 

 that cellulose is more easily decomposed bv micro-organisms than 

 pentosans, and hence is destroyed in the paunch to a greater extent. 

 In the small intestines, where the intestinal juice is supposed to take 

 part in dissolving the cellulose and the pentosans, the ratio remains 

 unchanged ; but in the blind intestine, where the cellulose is again 

 subjected to strong decomposition by bacteria, the ratio of pentosans 

 increases. In the case of the rabbit, the difierence in the digestibility 

 of the cellulose and the pentosans is also more marked in the blind 

 intestine. 



On the basis of these experiments it is stated that the digestion of 

 starch difiers essentiallj' from the decomposition of cellulose in the ali- 

 mentary canal. The products of the digestion of starch and cellulose 

 must, therefore, be ver}- difl'erent. Hence the nutritive value of the 

 substances in question must be quite difl'erent, not to mention the dif- 

 ference in loss of energy due to digestion. 



As to the nature of the digestion of pentosans, the similarit}' of the 

 changes in the different parts of the alimentary canal indicates that 

 the nature and the products of their digestion resemble those of cel- 

 lulose rather than those of starch. — r. fireiman. 



The digestibility of some nonnitrogenous constituents of certain 

 feeding stuffs, G. S. Fraps {Xortk Cdi'ollna Sta. Bid. 172, pp. J4D-G8, 

 70-80). — Using the data obtained in digestion experiments made with 

 sheep on several feeding stuffs, reported in earlier bulletins of the 

 station (E. S. R., 10, p. 667; 11, p. 276). and one on timothy hay not yet 

 reported, the author estimated the digestibility of several constituents 



