476 PRINCIPLES OF ANIMAL NUTRITION. 
abolizable, so that the above difference in gross energy would corre- 
spond to 745 Cals. of metabolizable energy. Of the metabolizable 
energy of the basal ration in excess of maintenance, 59.6 per cent. 
was recovered in the gain. If, then, the differences in organic matter 
consumed and in the digestibility of the basal ration had not offset 
some of the effect of the starch in Period 3, there would have been 
745 Cals. more of metabolizable energy disposable from the basal 
ration, and presumably the gain resulting from this would have been 
59.6 per cent. of 745 Cals., or 444 Cals. We have, then, by this 
method the following: 
Metabolizabl 
Enerey ‘Above,|  Sugeerot 
“Cals. Cals, 
Period 3 minus Period 4........... 0000000000: 6667 3752 
Correction for live weight................0204. 67 40 
6600 3712 
Correction for organic matter and for decreased 
digestibility 2.3 s00 cca vex ves woe vs cdaa vee ew i 745 444 
7345 4156 
Percentage utilization ............... 20.0000 [eee ee eee eee 56.6% 
Kellner’s results, then, assuming that the corrections are accu- 
rate, represent respectively the metabolizable and the utilizable 
energy of the digested matter of the starch itself, while the results 
as computed on the preceding pages represent, as was there pointed 
out, a balance between the various negative and positive effects of 
the addition of starch. In other words, Kellner attempts to com- 
pute the real as distinguished from the apparent utilization of the 
energy of the starch. The comparison on the opposite page of the 
percentages obtained in this way with those computed on p. 461 
will therefore be of interest. 
Kellner also computes by his method the distribution of the 
“ gross energy of the digested starch in Kithn’s experiments and in his 
own experiments on moderate rations. As calculated in Chapter X, 
pp. 325-6, the average loss of potential energy in methane was 12.7 
per cent. in Kithn’s experiments, and 10.11 per cent. in Kellner’s, 
while none of the potential energy of the digested starch passed 
