THE DIGESTIBILITY OP FEEDING STIFFS. 509 



by the writer at the agricultural experiment station at Mockern. 1 In 

 oue scries of experiments medium quality meadow hay, and in another 

 oat straw were each fed to steers and sheep. The composition and 

 digestibility of the feeding stuffs are shown in the following table: 



Comparative digestibility by steers <ni<l sheep of hay and straw. 



i . ■ 1 1 1 1 ■• > 



>ition 



of dry 

 matti r. 



Digestion coef- Digestible nutrients 

 ficients. in drv matter. 



Steers. 



Sheep. Steers. Sheep. 



Meadow ha v : Percent. Percent, Percent. Percent. Percent. 



Drv matter 100. 00 04.0 62.4 



Organic matter 92 01 07.1 64.6 62.4 60.0 



Crudeprotein 10.00 60.6, 57. 6.1 5.7 



Nitrogen-free extract 53.13 70.3 1 68.5 37.3 36.3 



Crndefat 2.58 I 61.0 56.7 1.6, 1.5 



Crudeliber 27.23 ! 63. 8 | 60.5 17.4 16.5 



Oat straw: 



Dry matter 100.00 57.2: 47.1 



Organic matter -. 93.22 58.1 47.7 54.2 44.5 



Crude protein 4.40 31.7 18.5! 1.4 0.8 



Nitrogen-free extract 49.13 57.7 49.4 24.3 



Crndefat 2.25 42 50.4! 1. 1.1 



Crude liber 2.7. I- 62.6 48.7 23.5 18.3 



11 appears from the above that there are differences between these 

 two classes of animals, which are to the advantage of the steers. The 

 sheep digested from the meadow hay slightly less and from the oat 

 straw about 10 per cent less dry matter than the steers. 



Without entering into a discussion of the causes of the lower digesti- 

 bility or resorption of the straw by sheep, it may be mentioned that the 

 difference observed for this feeding stuff is sufficient to suggest a further 

 investigation of this question of the relative digestibility by steers and 

 sheep. 



EFFECT OF THE DIGESTIVE FLUIDS. 



As already mentioned, the digestibility of a feeding stuff is calcu- 

 lated from the difference between the nutrients in the food eaten and 

 in the feces excreted. In this it is assumed that the feces consist 

 almost entirely of residues of the food and contain only small amounts 

 of substances derived from the body. As a matter of fact, the con- 

 stituents of the digestive fluids are for the most part resorbed again in 

 the intestines, as was shown by the investigations of Wildt with sheep. 

 Small quantities of these secretions, as mucin, bile, etc., pass off in the 

 feces, and under some circumstances may have an appreciable effect on 

 the coefficients of digestibility. If the amount of digestible nitroge- 

 nous substance calculated from the difference between the nitrogen in 

 the food and in the feces be compared with that estimated by artificial 

 digestion (treatment of the feeding stuff with acid pepsin solution) it 

 Mill be found that the latter method regularly gives the higher result. 

 This apparent increase by pepsin digestion amounts, according to the 



1 Nut yet published. 



