DIGESTIBILITY OF THE GRAIN SORGHUMS. 21 
Summary of digestion experiments with wheat bread in a simple mixed diet. 
Experi- 
ment No. 
Subject. 
Protein. 
Carbo- 
hydrates. 
Experi- 
ment No. 
Subject. 
Protein. 
Carbo- 
hydrates. 
226 
227 
228 
D. G. G 
R.L.S 
O.E.S 
Per cent. 
73.0 
88.8 
66.4 
Per cent. 
93.6 
98.1 
93.2 
229 
R.F.T 
Average 
Per cent. 
81.0 
Per cent. 
96.4 
77.3 
95.3 
The digestibility of fat and carbohydrate in both the corn and the 
wheat bread diets was very satisfactory, 94.5 per cent of fat and 95.9 
per cent of carbohydrate in the ration containing corn, and 94.1 per 
cent of fat and 95.4 per cent of carbohydrate in the wheat diet 
representing the percentages of available nutrients. The estimated 
value for the digestibility of the carbohydrate of corn bread alone is 
96.2 per cent and of the carbohydrate of wheat bread 95.3 per cent. 
An average of 38.4 grams of protein per man per day was 61.8 per 
cent digested in the experiments with corn bread and, although the 
average daily consumption of protein in the experiments with wheat 
was only 53.3 grams, this was 76.0 per cent available to the body. 
The estimated digestibility of the protein supplied by the corn bread 
alone is 59.9 per cent, and of the protein supplied by wheat bread. 
77.3 per cent. These values undoubtedly vary with the quantity of 
bran present in the flour and with other experimental conditions, 
such as the nature of the diet and the quantity of protein eaten. 
This opinion is in accordance with the conclusions of other investi- 
gators. Results of experiments by Woods and Merrill, 1 conducted 
in cooperation with the earlier work of the Office of Home Economics, 
indicate that all kinds of wheat bread are well digested and deserving 
of the important place given to them in the diet. These investi- 
gators found that the digestibility of the protein of wheat bread 
varied from 93.8 per cent for standard patent to 80 per cent for 
entire wheat flour. Snyder 2 also studied the comparative digesti- 
bility of protein in different grades of wheat flour, finding that 
although the entire wheat and graham flours contained more protein 
than the patent flours, the percentages of protein actually available 
to the body was greater in the patent flour. In experiments with 
Indian corn meal prepared for eating in several different ways, 
Merrill 3 found a digestibility of protein varying from 73 to 86 per 
cent. 
The digestibility of corn protein herein determined, 59.9 per cent, 
is somewhat lower than that usually reported, but it seems reasonable 
to conclude, in comparison with the preceding experiments with the 
grain sorghums in identically the same basal ration, that corn protein 
is more thoroughly digested than are the protein constituents of dwarf 
i U. S. Dept. Agr., Office Expt. Sta. Bui. 143 (1904), p. 33. 2 Maine Sta. Bui. 131 (1906). 
3 Idem,126 (1903), p. 46; 156 (1905X 
