472 
Journal of Agricultural Research 
Vol. XXXI, No. 5 
Since in the following pages the comparison is between only the 
later method used by Armsby and Fries and the newly modified 
method of computation, the former will be referred to, for the sake 
of brevity, simply as the “current method” and the latter as the 
“new method.” It should be borne in mind, however, that what is 
termed the “new method” of computation is merely a modification 
of the current method and is based on principles evolved and ex¬ 
pounded by Armsby. 
EXAMPLE 2, FROM EXPERIMENT 207 
In order to make clear the derivation of the net-energy values by 
the current method and by the new method, a detailed explanation 
of the several computations involved in both is given in this example 
(Table II): 
Table II. — Data for computation of net-energy values of timothy hay and grain 
mixture No. 1 
* w 
Average 
Dry matter eaten 
Metabolizable 
energy 
Heat 
Gain of 
energy 
Period No. 
Animal 
live 
weight 
Timothy 
nay 
Grain 
mixture 
No. 1 
Perkgm. 
of dry 
matter 
Total 
produc¬ 
tion <* 
1.. 
A 
Kgms. 
499 
Kgms. 
2.9349 
Kgms. 
1.9962 
Cals. 
Cals. 
12,061 
20,553 
6,235 
10,157 
Cals. 
10,171 
Cals. 
+1,890 
+6,518 
• ' -1,545 
+656 
2... 
A 
519 
2.9487 
4.7590 
i 
14,035 
7,780 
9,501 
3... 
A 
507 
2.9742 
1 2,096 
2,076 
4__ 
A 
514 
4.8920 
• The heat production used in this example, and in those following, has been corrected to a standard day 
of 12 hours standing and 12 hours lying according to the method of Fries and Kriss (10). , 
The Current Method 
COMPUTATION OF THE HEAT-INCREMENT VALUES OF HAY AND OF GRAIN 
Using the total observed heat production, corrected to the standard 
day of 12 hours standing and 12 hours lying as the starting point, 
the dry matter of the ration (kilograms) and the heat production of 
one period are compared with the dry matter and the heat production 
of the other periods. In case the comparison involves one feeding 
stuff, for instance hay alone, the difference in heat production is 
div ded by the difference in dry matter. The result is the heat incre¬ 
ment per kilogram of dry matter. In case the comparison involves 
a mixed ration of hay and grain, the difference in heat production due 
to the added hay is first computed by multiplying the latter by the 
heat-increment value previously determined from the hay rations. 
This is subtracted from the total difference in heat production, and 
the result is divided by the difference in grain to get the heat increment 
per kilogram of grain. Tables III and lY illustrate this computation, 
and give the heat-increment values of the timothy hay and of the 
grain mixture used in the experiment under consideration. 
There is only one heat-increment value for the hay, namely, 897 
Calories per kilogram of dry matter, which, of course, represents the 
average heat-increment value of the hay. For the gram there are 
three values—namely, l,215Calories, 1,394 Calories, and 1,319 Calories 
