MILK PRODUCTION AND BODY INCEEASE OF DAIRY COWS 
Hempel desiccator for two days; then a second charge was added 
and the capsule returned to the Hempel desiccator to remain until dry 
enough to ignite without the aid of any priming substance. The combus- 
tion in the bomb is complete when 20 atmospheres of oxygen is used. 
In the daily composite milk samples of the intermediate periods, 
the specific gravity and fat were determined, the latter by the Bab- 
cock method. Carefully calibrated bottles were used, the measured 
milk charges being weighed on an analytical balance. In the daily 
composite milk samples of the digestion and calorimeter periods 
total nitrogen and fat (by the Babcock method) were determined, 
and in the composite sample of each period determinations of specific 
gravity, fat, nitrogen, carbon, and energy were made. 
Samples of the daily feces were analyzed for total moisture. 
Since this is the first experiment ever reported in which the energy 
output of the milking animal was directly determined, and since the 
maintenance requirement of the cows was not determined, such an 
exhaustive study of the results is not submitted as will be possible 
when the data of subsequent experiments of this series shall have 
become available. At present, therefore, the more prominent results 
only will be pointed out, placing on record the experimental data 
with the hope that later results may shed additional light on the 
subject and serve to confirm the conclusions from this study. 
LIVE WEIGHTS AND RATIONS 
The live weights given in Table 2 are the average of nine daily 
weighings taken before watering and the same time of the day. At 
the time of weighing, small amounts of feed were sometimes noticed 
in the feed box; but these, with a few exceptions, were eaten after 
the animal had been watered. In the same table is recorded the total 
weight of daily feed. The feed was divided into two equal por- 
tions, the grain and hay being fed together at the specified hour. 
Table 2.- 
— Average daily weigh 
Is before 
watering, and 
weights 
of daily 
rations 
Cow No. 
Live weight Daily feed 
Period 
I 
Period 
II 
Period 
III 
Alfalfa 
hay 
Grain 
mriture 
Salt 
631 . . 
KOograms 
334.3 
Kilograms 
3fi0.fi 
Kilograms Kilograms 
390. 4 3. 280 
Kilograms 
4.900 
5.080 
5.590 
Grams 
10 
615. 
361. 8 | 366. 1 
367. 2 371. 8 
368.9 
3.364 
3.730 
10 
579 
10 
Cows 615 and 579 showed a slight tendency to gain in weight with 
the advance in the lactation period. Cow 631 was about dry in 
period II and her increase in weight is due in part to the rapid devel- 
opment of the fetus at her advanced stage of pregnancy. 
COMPOSITION OF FEED AND FECES 
The alfalfa hay, grain mixture, and the feces of the various periods 
were subjected to the customary feeding-stuff analyses, as reported 
in Table 3. The heat of combustion was also determined, the data 
being computed to dry matter. 
Particular attention is called to the loss of nitrogen on drying the 
dung by itself. This same loss also occurs in the dung-and-urine 
100177— 24f 2 
