Dec. 1, 1925 
Revised Net-Energy Values of Feeding Stuffs 
1085 
in heat production between periods compared, in relation to the 
differences in feed. This factor (26.3 Cals, per hour), representing 
an animal of 400 kg. live weight, is modified for animals of other 
weights in accord with the two-thirds power of the live weight, as 
follows: 
Live weight 
Factor 
Live weight 
Factor 
Live weight 
Factor 
Live weight 
Factor 
Kg. 
300_ 
Cals. 
21.7 
22.9 
24.1 
Kg. 
375_ 
Cals. 
25.2 
26.3 
27.4 
Kg. 
450.. ._ 
Cals. 
28.5 
29.5 
30.5 
Kg. 
525 
Cals. 
31.5 
32.5 
33.5 
325.. 
400_ 
475 _ 
550.. 
350.... 
425_ 
500_ 
575_ 
The correction to the standard day of 12 hours standing and 12 
hours lying is computed by determining the difference in hours 
between 12 (the standard) and the time actually spent in the stand¬ 
ing position, and multiplying this difference by the factor correspond¬ 
ing to the live weight of the animal. This correction is subtracted 
from the heat production as measured, or is added thereto, according 
to whether the animal stood more or less than 12 hours during the 
calorimeter day. For example, the daily heat production of a steer 
weighing 501 kg. was 10,754 Cals. The steer spent 9.25 hours per 
day in the standing position. The correction for standing is (12 — 
9.25) X 30.5=+84 Cals., and the heat production corrected to the 
standard day of 12 hours standing and 12 hours lying is 10,754 + 
84 = 10,838 Cals. If this animal had stood 14.75 hours per day the 
correction would be (12 —14.75) X30.5=—84 Cals., and to correct 
the daily heat production to the standard day of 12 hours standing 
and 12 hours lying the 84 Cals, would be subtracted. It should be 
noted that for the determination of the heat increment caused by the 
feed, and, consequently, for the determination of the net-energy 
value of the feed, the length of the standard day is immaterial. For 
a detailed discussion of this method and the derivation of the factors, 
the reader is referred to the original publication (10). 
DATA FOR THE DETERMINATION OF NET-ENERGY VALUES 
In order to compute the net-energy value of a feeding stuff, it is 
necessary to have from each of two or more periods of differing intake 
of the feed of interest, (1) the daily dry matter of the feed eaten, (2) the 
metabolizable energy of the ration (energy of the feed minus the 
energy of the excreta), and (3) the daily heat production by the 
animal, corrected to the standard day of 12 hours standing and 12 
hours lying. 
In recomputing the net-energy values of the feeds for which such 
values have been published from this institute, the data for dry 
matter of feed, for metabolizable energy, and for the daily heat pro¬ 
duction, as measured, remain as previously reported, except where 
arithmetical or other errors of work have been discovered; 3 but inas¬ 
much as the new method of correcting the heat production to a 
3 Attention is called to an error in the value for the average metabolizable energy per kilogram of dry 
matter of timothy hay in experiment 174 as reported in the following: H. P. Armsby and J. A. Fries, 
Net energy values of feeding stuffs for cattle, Jour. Agr. Research 3:441,444,1915. The value reported there 
is 1,674 Cals. The correct value is 1,953 Cals. For the linseed meal in this experiment the writers used the 
values for metabolizable energy, heat increment, and net energy given in the following: H. P. Armsby, 
The nutrition of farm animals, 743 p., illus., New York, 1917. 
