Feb. 2,1924 
Digestibility of Tested Grain Hulls 
249 
Gregoire (17) reported in 1907 on the method of Seidl and Bauriedl 
in which straw was treated under pressure with 3 per cent NaOH. The 
material was fed while still wet and was claimed to be fully as digestible 
as starch. 
After the outbreak of the World War, investigations of this nature 
became quite numerous. One of the first processes proposed was that 
of Oexmann, who utilized the straw pulp of the paper industry, mixing 
it with 35 per cent of molasses. The mixture was dried, ground, and 
placed on the market as “ Strohkraftfutter II.” With protein added to 
it, it was known as ‘‘Strohkraftfutter I.” 
Lehmann’s process of cooking the straw under pressure with varying 
concentrations of NaOH was also further experimented with at this 
time, but was found to be not economically sound, due to costly equip¬ 
ment and the necessity of handling large amounts of water. 
Colsmann’s process was devised to overcome these defects and con¬ 
sisted of cooking straw without pressure for 12 hours, using simple 
equipment. The element of time was the main consideration here, and 
in that respect the Muller process, which shortened the time somewhat 
by stirring, was an improvement over Colsmann’s method. 
The Dahlemer process is similar in principle to Colsmann’s and to 
Lehmann’s original method, cast-iron vessels being employed for the 
hydrolysis of the straw. 
Fingerling reports that Colsmann’s product had a digestibility of 60 
to 65 per cent (26, p. 290 ), while that of the Dahlemer process was 75 
per cent digestible (rj, p. 6). 
Unfortunately, we have not been able to find in the literature any 
original accounts of the Oexmann, Colsmann, Muller, and Dahlemer 
processes, but they are reported in some detail by Fingerling (26, p. 289 , 
290 ) and by Magnus (30, p. 1-4). Because of the lack of references we 
are unable to assign definite dates as to the chronological sequence of 
their publication or introduction into practice. It is inferred, however, 
from a careful study of the literature that they were all developed during 
the early part of the war. Other investigators about the same time 
were Stutzer (42), Dannfelt (9), Tollens ( 43 ), and Hansen ( 18 ). 
All of the processes devised for straw hydrolysis up to as late as 1917 
required as an essential feature of their operation the application of heat. 
In 1918 Beckmann put forward his process of hydrolysis in the cold, 
which was so much more simple and economical that it rapidly super¬ 
seded those already in use and became the subject of careful investigation 
by the German experiment stations and others. Since that time prac¬ 
tically all the literature on the subject (in Germany at least) deals with 
this process or modifications of it. The process has been patented, in 
Germany about 1919, and in the United States more recently (3). 
The essential features of the method are hydrolysis of the material 
with eight times its weight of 1.5 per cent NaOH in open vats for a 
comparatively short time—three hours is usually sufficient—draining off 
the liquor and washing with water until the product no longer turns 
red litmus paper blue. The process is carried on at ordinary temperature, 
and those who have thoroughly investigated the method claim that the 
hydrolysis is as complete at this temperature and in the relatively short 
time recommended as it is when the material is subjected to cooking 
either with or without pressure for longer periods of time. Also, the loss 
of valuable nutritive substance is very much reduced. 
