
DIGESTION EXPERIMENTS WITH SHEEP. 247 
seven days were devoted to preliminary feeding, during which 
the feces were not collected and each animal had the run of its 
pen. At the end of the first seven days the sheep were placed 
in a narrow stall where they remained during the five days of 
the digestion experiment proper. In these experiments, as in 
_ those with men, the metabolic products in the feces are counted 
as if they were part of the undigested residue of the food. 
The heats of combustion of the food and feces were determined 
by the bomb calorimeter, and the results taken as the measure 
of the fuel value. The nitrogenous matter of the digested 
food is not completely oxidized in the body, but a portion is 
eliminated with the urine in urea and kindred compounds. 
The potential energy of these compounds does not become avail- 
able to the body. Its amount is roughly calculated in the 
manner described on page 178, in the discussion under diges- 
tion experiments with men. ‘The assumptions there made 
probably give rather too low results. Late research seems to 
indicate that a larger factor should be assigned for the fuel 
value of the nitrogenous matter of the urine. This subject is 
now being studied by the Station. Meanwhile the values here 
given may be considered as approximately correct. 
General conclusions from these experiments will hardly be 
possible until more data are available. One point is, however, 
brought out very clearly. Among the feeding stuffs tested, 
those rich in protein, such as the legumes, are much more 
digestible than those with little protein, such as corn fodder, 
oat fodder, millet, and the like. 
Table 72, which immediately follows, gives a summary of 
the results obtained in the digestion experiments thus far 
made with sheep by the Station. These experiments are 
arranged, according to the character of the feeding stutts 
used, under the headings: milling products (with hay), cured 
fodders and hays, and green fodders and grasses. The details 
of experiments Nos. 1-9 will be found in the Annual Report 
for 1894, and Nos. 10-27 in the Report for 1895. The detailed 
account of the other experiments (Nos. 28-45) follow the 
summary table. 
