118 PRINCIPLES OF ANIMAL NUTRITION. 
Nitrogen | Nitrogen Gain of 
Period. Food per Day. of Food, *\jof Excreta,*| Nitrogen, 
Grms. Grms. Grms. 
I. 9Qdays. | Milk and horn dust ........... 2.75 3.35 —0.60 
II. 10 days. | Same + 22 grms. crude fiber...) 2.75 2.65 +0.10 
Til. 5 days. | Milk and horn dust ........... 2.70 3.03 —0.33 
IV. 4 days. | Same + 11 grms. cane sugar .. . 2.70 3.02 — 0.32 
V. 3days.t| “ +233 “ ...{ 2.70 2.73 —0.03 
Weiske { disputes v. Knieriem’s conclusion that cellulose dimin- 
ishes the proteid metabolism. He experimented upon a sheep, 
which was fed in a first period exclusively on beans. In succeeding 
periods the effect upon the proteid metabolism of adding to this 
ration, first, inferior oat straw, and second, starch was tested, the 
bean ration being diminished slightly in these periods in order 
to keep the total digestible protein of the ration as nearly uniform 
as possible. On the basis of a preliminary digestion trial with the 
straw, the quantity of starch was so adjusted as to supply, in Period 
III, according to computation, an amount of digestible carbohy- 
drates equal to the digested fiber and nitrogen-free extract of the 
straw of Period II, while in Period V it equalled the digested 
nitrogen-free extract only. Actual determinations of the digesti- 
bility of the mixed rations showed that this equality was approxi- 
mately, although not exactly, reached, the amount of digested 
starch being rather less than the computed amount. 
The results as regards the proteid metabolism as originally re- 
ported by Weiske are given in the first portion of the table on 
the opposite page. v. Knieriem,§ having criticised the results on 
the ground that the metabolic nitrogen of the feces was not taken 
into account, and that when this was done the experiments made a 
more favorable showing for the digested crude fiber, Weiske || has 
recalculated his results on the assumption that the feces contained 
0.4 grams of metabolic nitrogen for each 100 grams of dry matter 
digested, with the results shown in the second half of the table. 
* Not including that of the horn dust. 
+ Results regarded by the author as of doubtful value 
{ Zeit. f. Biol., 22, 373. 
§ Ibid., 24, 293. 
|| Zbid., 24, 553. 
{Compare Kellner, Landw. Vers. Stat., 24, 434; and Pfeiffer, Jour. f. 
Landw., 33, 149. 
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