320 PRINCIPLES OF ANIMAL NUTRITION. 
increased formation of hippuric acid and what part of it, if any, is 
to be ascribed to the presence of non-nitrogenous matter in the 
urine, the experiments afford no means of estimating. 
The Horse.—Zuntz & Hagemann’s results on the horse, p. 315, 
although the result of feeding mixed rations, may be conveniently 
considered here. The computed energy of the urine was 15.521 
Cals. per gram of nitrogen, equivalent to 2.483 Cals. per gram of 
protein. Assuming for the latter, as before, a value of 5.711 Cals., 
there remains for the metabolizable energy 3.228 Cals. per gram. 
PROTEIN OF CoaRsE Foppers.—Almost the only data on this 
point are those afforded by Kellner’s experiments upon cattle. In 
those in which coarse fodders were used alone we can of course 
compute the metabolizable energy of the protein directly from the 
amount digested and from the energy of the urine. In those 
experiments in which coarse fodders were added to a basal ration 
we can compare the two experiments in the same manner as those 
upon gluten, neglecting, as in that case, the differences in the non- 
nitrogenous nutrients digested. 
Passing over the details of the computation, the final results, 
including the metabolizable energy of the digested protein com- 
puted upon the assumption that its gross energy equals 5.711 
Cals. per gram, are as given in the table on the opposite page.* 
The writer’s experiments on timothy hay, the results of which 
as regards the energy of the urine have already been given on p. 314, 
when computed in the same manner as the above experiments give 
the following results for the metabolizable energy of the digested 
protein: 
teen Waste: Gan seemed as neath 2.625 Cals. 
OO Divine arte sae Gs hae a Son ahaa Bu a 2.830 “ 
OS Donnie Gish iy Sones nee ahah cSt ae 3.716 “ 
AVETARC citaina ciara sew eters 3.057 “ 
Influence of Non-nitrogenous Matter of Urine.—In the previous 
paragraphs there appeared reasons for supposing that the processes 
of proteid metabolism are cssentially the same in all domestic 
* The figures given in this table for digested protein, energy, etc., refer 
solely to that derived from the coarse fodder and not to that of the total 
ration. 
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