29 3 REPORT OF THE DIRECTOR OF THE 
Since from two-thirds to three-fourths of the weight of the 
animal is water, the increase in water-free matter was, upon an 
average, about one-half a-pound, so that it will be seen that, even 
with young animals, the growth of which is entirely satisfactory, 
the amount of food actually appropriated by them for growth over 
and above that needed to replace the waste of tissue, does not 
exceed six per cent of the dry matter of the food consumed by 
them. ; 
In‘a series of experiments given in detail in the feeding trials, 
eight animals averaging 930 pounds in weight, four cows in milk, 
two heifers and two fattening steers; there was fed daily 175.3 
pounds of dry matter, and there was found in the dung 68.1 
pounds of dry matter; 12.23 pounds in the urine; 7.38 pounds in 
milk and 1.56 pounds in increase of weight during the experiment, 
a total of 89.3 pounds, thus leaving 86.0 pounds of dry matter in 
the food unaccounted for, which amount must have been consumed | 
in supplying the other demands of the animals. 
Tt has been estimated that the average man exhales as carbonic 
acid eight and one-half ounces of carbon daily or upon an average 
ninety-one and one-half per cent of the carbon in his digested 
food. The eight animals under experiment had an aggregate 
weight of 7,534 pounds; eight and one-half ounces of carbon is 
equivalent to 20.6 ounces of average carbohydrates as starch and 
sugar, those constituents of the food which probably are utilized 
for the production of animal heat and supplying muscular power. 
Supposing the demands of these animals for these purpose to be 
equal in proportion to their weight and that the average man 
should weigh 140 pounds, these eight cattle would have required 
69.3 pounds which leaves but 16.7 pounds of the dry matter of the 
food unaccounted for. 
If we consider the case of the four cows giving milk during the 
feeding experiment, we find the daily dry matter of their food to 
be 79.7 pounds, of which there was obtained 31.0 pounds in the 
dung, 5.62 pounds in the urine, 7.38 pounds in the milk, or a total 
of forty-four pounds, leaving 35.7 pounds to be accounted for; and 
as these cows weighed upon an average during the trial 3,798 
pounds in the aggregate, they would have required upon thesame 
estimate as before 34.8 pounds of dry matter of food for heat and 
work, an amount almost exactly equal to the quantity uneeconniees 
for. 
