324 PRINCIPLES OF ANIMAL NUTRITION. 
i- ‘ E f Uri E 
mal, | Period. (Comecten). Cals, | Mothan’ Gata 
D 3 With oil................ 2851:2 2909.0 
D 1 Basal ration............ 2407.0 2957 .0 
Differences............ —55.8 —48.0 =o 
E 3 Wath Oil goc.c sawed swasias 2026.2 2640.8 
E 1 Basal ration............. 2312.9 2950.4 
Differences............ —286.7 —309.6 
F 5 With oil..............2. 1455.0 1369.1 
F 3 Basal ration............ 1530.0 2560.7 
Differences............ —75.0 —1191.6 
G 5 With oil... ........0 0... 1452.1 2371.2 
G 3 Basal ration............ 1359.6 2524.7 
Differences............ 92.5 —153.5 
as Kellner does that none of the energy of the fat was lost either in 
the hydrocarbons or in the urine, and that consequently the metab- 
olizable energy of the digested fat was the same as its gross energy, 
namely, 8.821 Cals. per gram, as given on p. 308. If we assume that 
the ether extract of hay behaves like the peanut oil, taking no part 
either in the production of methane or in the loss of energy through 
the urine, its metabolizable energy would likewise be the same as 
its gross energy, namely ,8.322 Cals. per gram, as computed on p. 305. 
No results upon the metabolizable energy of the ether extract are 
available in the case of other species of herbivorous animals. 
Carbohydrates.—Those of Kellner’s experiments in which 
starch, as a representative of the readily digestible carbohydrates. 
and extracted straw, consisting largely of “crude fiber,’ were added 
to the basal ration afford data for an approximate computation of 
the metabolizable energy of this group of nutrients in the ox, and 
experiments by Lehmann, Hagemann & Zuntz afford partial data 
for the horse. 
Starcu.—The results of the Méckern experiments, as recorded 
in Tables III and IV of the Appendix, show that the starch had 
but a slight effect upon the amount of potential energy carried off 
in the urine of the ox, although the general tendency was to 
