Dec. 1 , 1925 
Revised Net-Energy Values of Feeding Stuffs 
1093 
result has been, in all probability, rather commonly at least, inter¬ 
mediate between these extremes, there being no way to determine 
positively the net effect of this effort to correct for refusal of feed. 
In fact, refusal of feed introduces most perplexing complications, 
and, if considerable in amount, is fatal to the significance of the 
results. 
For present purposes the writers leave this matter as it stands, 
with a citation of the published figures representing amounts of feed 
refused, and an acknowledgment of the fact that this has been a source 
of error—commonly a minor one, it is true, but sometimes extensive. 
As for the bearing of the critical temperature in this connection, 
there is evidence to suggest, in some periods of restricted feed intake, 
that the heat incident to the vital processes and the utilization of the 
feed was insufficient to maintain the normal temperature of the 
animal, the subject being obliged, therefore, to oxidize body substance 
to make good the deficit. In such a case the heat increment would 
exceed the amount derived from the feed, and so would be in error as 
related to the feed alone. 
In the present lack of definite evidence as to what the critical 
temperature for cattle is, under the various conditions in accord with 
which it is believed to vary, we are unable to say positively that this 
factor is responsible for certain anomalous results obtained, but the 
presumptive evidence is of such weight, in the writers 7 judgment, as 
to warrant withholding some of these results until further information 
as to critical temperatures shall remove the question as to their 
significance. 
In other experiments, however, in which there was ground for 
suspecting error on this account, it was possible to use the results by 
computing the maintenance requirements from the results of other 
experiments with the same subjects, as will be explained in the 
following paragraph. 
MAINTENANCE REQUIREMENT OF NET ENERGY 
In computing the net energy required for maintenance, the general 
procedure as outlined was followed, except in two series of experiments, 
namely Nos. 186 and 200. In these cases, on account of the ground 
for suspicion that the temperature in the calorimeter was below the 
critical for the subjects in some of the periods, we have computed the 
maintenance requirements from data obtained in other experiments 
with the same animals. In so doing the writers computed this quota 
in proportion to the two-thirds power of the live weight. Thus the 
maintenance requirement of steer I in experiment 186 was computed 
from the maintenance of this animal as determined in experiment 179, 
while the maintenance requirements of steers A and B m experiment 
200 were computed from the maintenance requirements of these 
animals as determined in experiment 207. 
In this connection it should be stated that the reason for not 
including in this paper the experiments with the young growing steers, 
namely experiments Nos. 190 and 208, to which reference has already 
been made, is that these experiments are also subject to the same 
suspicion of having been affected by subcritical temperatures, and, 
as the writers have no adequate basis for computing the net-energy 
