18 BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 
Summary of digestion experiments with kaoliang bread in a simple mixed diet. 
Experi- 
ment No. 
Subject. Protein. 
Carbohy- 
drates. 
Experi- 
ment No. 
Subject. 
Protein. 
Carbohy- 
drates. 
378 
379 
380 
381 
393 
I). G. G 
A. J.H 
R. L. S 
0. E. S 
D. G. G 
Per cent. 
26.8 
16.1 
15.0 
34.0 
12.0 
Per cent. 
96.4 
96.5 
95.4 
97.5 
94.8 
394 
395 
396 
A. J. H 
R.L. S 
O.E.S 
Average 
Per cent. 
15.2 
16.0 
23.4 
Per cent. 
96.7 
96.2 
96.5 
19.8 
96.3 
In the experiments with kaoliang, notwithstanding the fact that 
the subjects ate nearly a pound of this bread daily, it supplied on 
an average only 41 grams of protein and 288 grams of carbohydrate 
per man per day. As the data recorded above show, the bread pro- 
tein was found to be only 19.8 per cent available to the body, while 
the digestibility of carbohydrate proved to be 96.3 per cent. 
SUMMARY OF DATA ON THE DIGESTD3IIJTY OF THE GRAIN-SORGHUM BREADS. 
Considering the experiments with the sorghum gingerbreads as a 
whole, the digestibility of the protein of bread alone averaged less 
than 50 per cent, while that of the carbohydrate constituent of the 
bread was found to be uniformly high. That the digestibility of the 
carbohydrate from the sorghum meals alone is practically identical 
with that of the breads alone is evident from the fact that the only 
accessory carbohydrate present in the breads was a relatively small 
quantity of molasses — a carbohydrate whose digestibility is 98 per 
cent. Moreover the averages for the digestibility of carbohydrate 
from kafir, feterita, milo, and kaoliang breads are practically iden- 
tical with the value usually given for the average simple mixed diet — 
namely, 97 per cent. 1 The close agreement of these values is of 
particular interest, for it indicates that the low values obtained for 
the digestibility of protein are not due to errors in the collections of 
the feces. 
The subjects reported as a rule that they seemed to be in normal 
condition throughout the experimental periods. The diets contain- 
ing the grain sorghums seemed to assist materially the peristaltic 
action of the intestine — an effect which was probably due to the 
large bulk of unassimilated material which the sorghum meals sup- 
ply. In one or two instances the subjects reported sensations of 
hunger and nervous headache, but this was probably due to the fact 
that too little nutritive material was eaten to supply the body needs. 
It is thought that sufficient experimental data have been accumu- 
lated in this series of experiments to permit of an accurate compari- 
son of the digestibility of the sorghums one with another. In order 
to ascertain their digestibility as compared with other cereals, a series 
of check experiments has been made with corn and wheat meal pre- 
pared in the same way and eaten with the same basal ration. 
• Connecticut Storrs Sta. Rpt. 1901, p. 245. 
