32 



The number of experiments up to the present time is much less than 

 those with hay, straw, and other crude fodder -mater mIs, as the Germans 

 call them. The followiag are mean results : 



KiB<l <ii' food. 



Amounts digested in 100 parts. 



Total organic 

 substance. 



Potatoes 



Turnips 



Bean-meal, (iin'boltfMi) 



Bran (of spelt, bearded wheat) 



Rape-cakes 



Cotton seed cakes 



89 

 90 

 93 



84.8 

 38.8 

 49.7 



Crude fiber. 



70 

 C9. 1 



Fat. 



99.7 



88.2 

 69.8 

 90.8 



Carbo-hy- 

 drates.' 



94.9 



97.7 



94 



90.8 



79.6 



46.2 



Albumin- 

 9id.s. 



64.9 

 76.8 

 94.6 

 72.5 

 77.9 

 73.8 



The digestibility of cotton-seed cakes and their consequent value 

 as fodder is one of special interest in this country. 



Wolif, by whom the experiments (four in number) with cottonseed 

 cakes were performed, (Ys.-St., XIV, 1871, p. 409,) remarks that ''The 

 chief value of oilcakes is due to their large content of albuminoid and 

 fatty substances, and it is interesting that these ingredients in cotton- 

 seed cakes, according to direct experiments, are scarcely less digestible 

 than in other dil-cakes. That less of the crude fiber was digested was 

 due to the amount of leathery husks occurring with the unshelled seeds 

 of the oil-cakes." 



The effect of addition of the more digestible substances, as meal, oil, 

 and potatoes, to rations of crude fodder, as hay and straw, upon the diges- 

 tion of the latter, has also been made a subject of extensive investiga- 

 tions. Some of the results are as follows : 



1st. As to effect of easily digestible substances, rich in nitrogen and 

 gluten, such as cracked beans, &c. Experiments at Weende, Moeckeru, 

 and Hohenheim, indicate that the digestion of hay, straw. &c., is not es- 

 sentially affected by presence of these substances. 



2d. As to the ett'ect of easily digestible carbo-hydrates, starch, sugar, 

 and materials rich in these substances, as potatoes. The general effect 

 of these substances when added in considerable quantities is to decrease 

 the digestion of crude fodder-materials. For instance, in a series of ex- 

 periments performed by Wolff', at Hohenheim, (Ys.-St., 1871, XIV, p. 

 405,) in which sheep were fed with clover-hay alone, C3.7 per cent, of the 

 albuminoid and 51.2 per cent, of the crude fiber were digested. In suc- 

 ceeding periods mixed rations of clover-hay and potatoes were given, the 

 proportion of the potatoes being increased in successive periods. The 

 proportion of albuminoids digested from the hay in these successive 

 periods was gradually reduced from 63.7 to 45.7 per cent., and that of the 

 crude fiber from 51.2 to 43.3 per cent. 



The practical applications of the results of the experiments of the two 

 classes mentioned are very important. It has been seen that straw is 

 nearly as digestible as hay. Indeed, Henneberg found that his oxen 

 digested as much material' from 20 pounds of straw as from 17 pounds 

 of hay. There was, however, a great difference in the composition of the 

 digested material. That from the hay contained more nitrogenous mat- 

 ter, albuminoids, and less non-nitrogenous matter, fat, carbo-hydrates, 

 and crude fiber, than that from. the straw. In other words, the hay fur- 

 nished a diet richer in nitrogen than the straw. Straw would be too poor 

 in nitrogen to make alone a good diet for ordinary feeding purposes. 

 But by mixing it with some material rich in nitrogen, as clover-hay or oil- 

 cakes, the proper proportion between nitrogenous and non-nitrogenou& 



