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. 



E xperi- 

 ment No. 



Subject. 



Protein. 



Carbohy- 

 drates. 



378 



D.G. G 



A. J. II 



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 



396 



A. J. H 



Per cent. 

 15.2 

 16.0 

 23.4 



Per cent. 

 96.7 



379 



R. L. S 



0. E. S 



Average 



96.2 



380 



381 



393 



R. L. S 



0. E. S 



D. G. G 



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 DIGESTIBILITY 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. 



i Connecticut Storrs Sta. Rpt. 1901, p. 245. 



