REVISED NET-ENERGY VALUES OF FEEDING STUFFS 
FOR CATTLE 1 
By E. B. Forbes, Director, and Max Kriss, Associate in Animal Nutrition, 
Institute of Animal Nutrition, Pennsylvania State College 
INTRODUCTION 
One of the chief purposes of the work with the respiration calo¬ 
rimeter at the Pennsylvania Institute of Animal Nutrition has been 
to determine the total expenditure of energy by animals in the 
utilization of feed for maintenance and production, the difference 
between the gross energy and the energy losses and expenditures 
of utilization constituting the net-energy value. 
The methods employed and the results obtained with steers, 
during the years 1902 to 1915, have been reported in articles by 
Armsby and Fries (I, 2, 3, 4, 6 , 7, 8, 9). 2 The derivation of these 
values involves comparisons of heat production in periods of unlike 
feed consumption, these comparisons being dependent upon uniform 
conditions as to expenditure of energy for maintenance, especially as 
determined by the time spent by the animal in the standing and the 
lying positions. 
In recent studies at this institute (10, 11), the evidence obtained 
has disclosed imperfections in the treatment of the experimental data 
and in the computations which have led to the published net-energy 
values. These studies have led (1) to a new method of correcting 
the heat production of the experimental animal to a standard day, 
as to standing and lying, and (2) to an important change in the 
method of computation of the net-energy values. These improved 
procedures, which have been described in detail elsewhere (10, 11), 
are of such importance as to necessitate the recalculation of all of 
the net-energy determinations of feeds for steers which have been 
published from this institute, and the corrected results are set forth 
in this paper. 
EXPERIMENTS AND ANIMALS 
The experiments involved in this recomputation include 12 series, 
comprising 71 experimental periods, with 9 different steers, varying 
in age from 20 months to approximately 60 months at the beginning 
of the several experiments. 
This covers all of the net-energy values of feeds for steers which 
have been determined at this institute (1, 2, 3, 4, 6, 7, 8, 9), except 
the results of two series of experiments (Nos. 190 and 208) with 
young, growing steers, which have been omitted from this paper for 
reasons which will be explained. 
Data relating to the steers which served as experimental subjects 
in these investigations comprise Table I. 
1 (Received for publication Feb. 18, 1925; issued January, 1926. 
^Reference is made by number (italic) to “Literature cited” p. 1098. 
Journal of Agricultural Research, 
Washington, D. C. 
(1083) 
Vol. XXXI, No. 11 
Dec. 1, 1925 
Key No. Pa.-16 
