Feb. 2,1924 
Digestibility of Tested Grain Hulls 
261 
Table VIII .—Effect of varying strengths of sodium hydxoid in increasing digestibility of 
fibrous material a 
Percentage increase over untreated hulls. 
Solution used. 
Total 
dry 
matter. 
Crude 
fiber. 
N-free 
extract. 
Pento¬ 
sans. 
Lignin. 
1 per cent NaOH (oats). 
1 per cent NaOH (barley). 
1.5 per cent NaOH (oats). 
1.5 per cent NaOH (barley). 
1.5 per cent NaOH (rice). 
3 per cent NaOH (rice). 
94.17 
14 - 54 
122.43 
37 - 57 
486. 72 
583- 90 
57 - 45 
16. 72 
73-24 
81.47 
135 - 76 
in. 67 
89. 76 
25.00 
131.92 
41-35 
284. 63 
355 - 51 
97.91 
36.90 
105.46 
75 -19 
1,674. 25 
1,170- 36 
252.89 
84-97 
232. 68 
(2) 
00 
00 
a The cottonseed hulls and flax shives are not included in this summary because of the negligible effect the 
soda solution had on their digestibility, 
ft Negative. 
e Averages not available for lignin because of varying results in its digestibility. 
As a rule, increases in the relative amount of a component due to treat¬ 
ment were accompanied by an increase in its percentage digestibility. 
Taking into consideration both the loss in weight and the increased 
digestibility due to the action of the soda (see Tables IV and VI) we obtain 
net gains as shown in Table IX. 
Table IX .—Average net gain in total digestible dry matter and in the important digestible 
nutrients of oat hulls and barley hulls on the basis of 100 pounds of dry matter treated 
Material. 
Total di¬ 
gestible 
dry 
matter. 
Digest¬ 
ible 
crude 
fiber. 
Digest¬ 
ible 
N-free 
extract. 
Digest¬ 
ible 
pento¬ 
sans. 
Digest¬ 
ible 
lignin. 
Oat hulls, treated 1 per cent NaOH. ;... 
Oat hulls, treated 1.5 per cent NaOH. 
Barley hulls, treated 1 per cent NaOH. 
Barley hulls, treated 1.5 per cent NaOH. 
7- 72 
31.04 
h 4 - 55 
5 - 79 
5-47 
0 19.14 
2. 81 
8. 18 
3.60 
n -59 
&3- 68 
11.31 
11.81 
IS. 88 
4.81 
8.46 
a 7.06 
2.94 
1.97 
00 
• Referring to Tables IV and VI it will be seen that the total crude fiber and total lignin of oat hulls 
each showed a net gain instead of a net loss after treatment. As already noted, this is impossible, so the 
results in question are obtained by assuming that no loss of these constituents was involved, 
ft This result represents a net loss. 
c Digestibility of lignin in this instance was a minus quantity. 
Considering the net gains as shown in the table, it can be said that 
with one exception (barley hulls, 1 per cent NaOH) the increase in digesti¬ 
bility outweighed the loss by solution in the soda. It is questionable, 
however, whether in those materials showing the smaller gains the in¬ 
crease would offset the cost of 'treatment. The extra 0.5 per cent of 
sodium hydroxid apparently makes a great difference in the final result. 
The barley hulls probably would have made a more favorable compari¬ 
son with the oat hulls had they not contained so much starchy material. 
Unfortunately, the separation of the endosperm from the hull had not 
been nearly so complete as in the case of the oat hulls (due in part, prob¬ 
ably, to the greater tenacity with which the barley hull clings to the 
endosperm, or possibly to a less perfect mechanical method of separa¬ 
tion) , and as a result there was quite a large amount of the floury portion 
of the grain adherent to the hulls. 
On a dry-matter basis the digestible matter in a ton of oat hulls was 
increased by treatment with 1.5 per cent NaOH from 725 pounds to 1,345 
