MILK PRODUCTION AND BODY INCREASE OF DAIRY COWS 3i 
that results in different periods with different kinds or quantities 
of feed did not agree so closely as was to be expected in consideration 
of the time of standing and lying and the respective rates of heat 
emission. 
This led Armsby to collect the available data and, after a careful 
study of the relation of change in quantity of feed and of variation 
in length of time spent standing and lying to increase in heat emission 
due to standing, to make the following statement (12): "It is clear, 
therefore, that despite the apparent uniformity of experimental 
conditions the metabolism of the animals was affected by influences 
other than the feed or the proportion of time spent standing." That 
is, the total observed difference in heat emission per minute between 
standing and lying can not be ascribed entirely to the muscular 
work due to standing. 
The following are some of the outstanding experimental facts as 
to heat emission in relation to standing and lying : 
The average heat emission per minute of standing is always much 
greater than that per minute of lying. 
Body temperature does not change w T ith change of position. 
With an increasing ration there is usually an increment in the heat 
emission per 24 hours of standing. There is, however, a lack of 
uniformity in the results, and negative differences have also been 
observed. 
With an increase in feed there is almost invariably an increase in 
methane fermentation, and a part of the heat of fermentation will 
be included in the increment of standing. 
An increase of a few kilograms in live weight does not noticeably 
affect the heat emission during standing. 
There is no strict quantitative relation between the heat emission 
per minute and the length of time spent standing. 
M0llgaard (13), discussing the results of standing and lying, did 
not find the consumption of oxygen to vary with the time spent in 
these positions, and believes that there is in the end a compensation 
taking place within the animal of such nature that after a longer 
period of standing, and therefore greater fatigue, the metabolism of 
the animal decreases on lying down to a greater extent than after a 
shorter period of standing. However, experiments of the writers 
cover many instances in which long periods of standing do not 
influence the heat emission during lying to a greater extent than do 
shorter periods; and M0llgaard's hypothesis does not explain the 
irregularities in the oxygen consumption, or the processes involved 
in producing such differences in heat emission as nave been noticed 
in the calorimeter experiments. 
Observations on the heat emission during lying and standing, 
together with the fact that at certain periods of the day the oxygen 
consumption 4 of the animal does not follow the carbon-dioxide pro- 
duction, would seem to indicate that conclusions can not be based 
on short sections of the experimental day since these are not reliably 
typical of the whole day or of the prevailing habit of life of the animal. 
That it requires energy for an animal to lie down and to get up, 
and muscular energy to support and balance the body in a standing 
position, is self-evident, but as to the exact quantity of energy thus 
used the evidence at hand does not warrant a definite conclusion. 
4 Unpublished data of the institute. 
