AGRICULTURAL EXPERIMENT STATION. 61 



The Comparative Digestibility of Wheat Bran and 

 Wheat Middlings. 



The wheat bran (shorts,) which is at the present time one of 

 our most important commercial cattle foods, is quite different 

 mechanically and chemically, we may believe, from that produced 

 by the earlier processes of milling, being coarser and more nitro- 

 genous. The mechanical difference is apparent to the eye, while 

 the change in composition is seen by comparing earlier analyses 

 with those given in this report. The average content of protein 

 in eight samples of bran analyzed by Storer and Johnson* previ- 

 ous to 1877, is given below in comparison with the average of the 

 samples collected last winter by this Station. 



Range of per cent. Averaare per cent, 

 of protein. of protein. 



Storer & Johnson, eight analyses, 11.13% to 13,91% 12.87% 



This Station, six analyses, 16.38% to 17.69% 16.89% 



Armsbyt has previously called attention to the difference be- 

 tween roller bran and that produced in former years. 



The only digestion experiments with wheat bran which are re- 

 corded were made in Germany, and there seems to be no evidence 

 than the experimental food was similar to our roller bran. In 

 fact, there is every reason to believe that the majority of the 

 German tests were made with quite different material. The diges- 

 tibility of middlings does not seem to have been determined any- 

 where, at least the German tables of digestion coefficients make 

 no mention of this feeding stuff, though it is possible that the term 

 bran (Kleie) has been applied to material which in this country 

 would be called middlings. It seems reasonably certain, however, 

 that there is here recorded the first determination and comparison 

 of the digestibility of American roller bran and middlings. 



Plan of Experiment. The animals used were wethers, as in 

 former experiments, and the general method of procedure was the 

 same as heretofore observed. The determination of the digesti- 

 bility of a grain or other concentrated food by ruminants requires 

 a modification of the plan followed in the case of a hay, for the 

 reason that a sheep cannot well be fed on bran alone, or corn 

 alone. It seems to be necessary to feed a fodder such as hay with 



* See Bulletin I, Bussey Institute, and Report of Conn. Agricultural Experi- 

 ment Station, 1877. 

 t See Report of Wis. Experiment Station, 1885, p. 86, 



2-P 



