Sept. 1, 1925 
Net-Energy Values of Feeding Stuff's 
483 
experiment as even more unsatisfactory. Without going into the 
causes for these results here, this experiment may serve to show how 
it is possible, by the new method, using a previously determined main¬ 
tenance value for the animal, to reveal the general character as to 
accuracy of the experimental data. 
The average net-energy value per kilogram of dry matter of the red 
clover hay, computed From the data of series a according to the 
current method, would be 2,076 — 321 = 1,755 Calories, and computed 
from the data of series b, impossible values, as indicated in the table. 
Experiment 179 was a satisfactory experiment with the same steer, 
conducted one year before experiment 186, with the same kind of feed 
as in experiment 186 (red clover hay) in two of the four periods. The 
maintenance requirement of the animal, computed from the revised 
figures for heat production, was found to be 6,618 Calories of net 
energy. The average live weight of the animal during that experi¬ 
ment was 528 kilograms, as compared with 572 kilograms during 
experiment 186, differing by only 44 kilograms. The maintenance 
requirement of the steer during experiment 186 may therefore be com¬ 
puted with a fair degree of accuracy in proportion to the two-third 
power of the live weights as follows: 
6,618 X (§|)2/3=6,981 Calories. 
By the use of this value for maintenance, approximate net-energy 
values of the red clover hay in experiment 186 may be computed as 
shown in Table XX. 
Table XX .—Computation of net-energy values of red clover hay 
Period No. 
Dry 
matter 
eaten 
Net 
energy 
for 
main¬ 
tenance 
Gain 
Total net 
energy 
of ration 
Net en¬ 
ergy per 
kilogram 
of dry 
matter 
Kgms. 
2.9333 
Cals. 
6,981 
6,981 
Cals. 
-4,675 
-5,398 
Cals. 
2,306 
Cals. 
786 
16..... 
2.9333 
1,583 
6,403 
540 
2a _ 
5.0253 
6,981 
-578 
1,274 
26. 
5.0253 
6,981 
-423 
6,558 
1,305 
1,206 
3a . 
4.1391 
6,981 
-1,991 
-2,062 
4,990 
6. .. ... 
4.1391 
6,981 
4,919 
1,188 
The net-energy values as computed in Table XX are in fair agree¬ 
ment for periods 2 and 3 of each series, while those of period 1 are 
abnormally low. This points to an abnormally high heat production 
in period 1 of each series, as the variation in the metabolizable-energy 
values in the different periods is only slight (Table XVIII). In other 
words, the results given in Table XX indicate that period 1 of each 
series was mainly responsible for rendering the whole experiment 
worthless when computed by the current method. The new compu¬ 
tation indicates that the results of periods 2 and 3 of both series a and 
b are fairly accurate. The advantage of such a computation is obvious 
SUMMARY 
By a critical analysis of the methods of this institute for the compu¬ 
tation of the net-energy values of feeds, from results of respiration 
calorimeter experiments, previously unsuspected defects have been 
revealed. 
CEREAL INVESTIGATIONS 
