478 
Journal of Agricultural Research 
Vol. XXXI, No. 5 
average net-energy values of the hay and of the grain as obtained 
by the two methods. Apparently, the determination of the gains 
of energy by the animal in each period, and the use of a determined 
instead of an assumed average value for the net energy required for 
maintenance, are chiefly responsible for the difference in the average 
net-energy values as computed by the two methods. As regards 
differences in live weight in relation to the maintenance requirement 
of the animal, both methods assume that the variations in weight 
in one series of experiments are largely due to “fill,” that is, to 
variations in the content of the digestive tract, rather than to any 
considerable change in the body proper, and that the actual main¬ 
tenance requirement is not greatly affected. 
In order that a full appreciation may be had of the differences 
between the two methods, in their application to different experi¬ 
ments, the following examples and discussion of results are presented. 
Example 3, from Experiment 211 
Table IX .—Data for computation of net-energy values of mixed hay and hominy 
chop 
Period No. 
Animal 
Average 
live 
weight 
Dry matter eaten 
Metabolizable 
energy 
Heat 
produc¬ 
tion* 
Gain of 
energy 
Mixed 
hay 
Hominy 
chops 
Per kilo¬ 
gram of 
dry 
matter 
Total 
1 .... 
Steer 
D 
D 
D 
D 
D 
Kgms. 
460 
432 
470 
455 
428 
Kgms. 
6.2042 
X. 7473 
3.9105 
3.4983 
1.7864 
Kgms. 
Cals. 
1,829 
Cals. 
11,348 
9,435 
21,406 
6,958 
3,276 
Cals. 
11,710 
9,665 
14,123 
9,302 
8,020 
Cals. 
-362 
-230 
+7,283 
-2,344 
-4, 744 
2. .. 
1.7637 
3.9488 
3 ___ 
4.... 
1,990 
1,834 
5 __ 
• Revised; see footnote to Table II. 
Table X .—Heat increment per kilogram of dry matter a 
Feeding stuff 
Periods compared 
Heat in¬ 
crement 
per kilo¬ 
gram 
Mixed hay__ -- ___ 
1 and 4.. 
Cals . 
890 
Do_______ 
4 and 5_ ... 
750 
Do________ 
1 and 5.. 
835 
Do_______ 
Average of all.. 
825 
Mixed hay and hominy chop___ __ 
2 and 3.. _ _ 
1,025 
951 
Computed for hominy chop____ 
2 and 5__ 
DO _:___ 
3 and 4.. 
1,134 
1,226 
Do. .. ______ 
2 and 3__ 
• Computed from the revised figures for heat production. 
The computation of the average net-energy values of the mixed 
hay, and of the hominy feed, according to the current method, from 
the data of Tables IX and X, would be as follows: 
Mixed Hay. —Average metabolizable energy per kilogram of dry 
matter —1,884 Calories. Heat increment per kilogram of dry matter 
obtained by comparison of the greatest and least amounts of feed 
(periods. 1 and 5) =835 Calories. Average net-energy value per 
kilogram of dry matter, 1,884 — 835 = 1.049 Calories. 
