MILK PRODUCTION AND BODY INCREASE OF DAIRY COWS 
21 
quently shown to be necessary. Further, the writers are not sure 
that the rather sudden temperature changes recorded indicate cor- 
rectly the temperature changes of the whole body. In view of these 
uncertainties the small variations, a few tenths of 1 degree Fahren- 
heit, while in the calorimeter are of doubtful significance; and, there- 
fore, in this experiment no corrections have been made for these 
apparent changes in body temperature. 
CHANGES IN LIVE WEIGHT DURING THE CALORIMETER EXPERIMENT 
Between the time of entering and leaving the respiration calo- 
rimeter there is frequently a considerable change in the live weight 
of the animal. This change is due especially to variation in the 
amount of water consumed; also, to an important extent, to irregu- 
larity in the voiding of excreta; and, further, to actual gain or loss 
of body substance. 
Table 17. — Changes in live weight of the cow while in the calorimeter 
Period I 
Period II 
Period III 
Gain 
Loss 
Gain 
Loss 
Gain 
Loss 
Cow 631: 
Water 
Grams 
Grams 
18, 894. 2 
66.0 
Grams 
5, 585. 7 
"I,"332.T 
Grams 
Grams 
Grams 
10, 536. 2 
Dry matter irregularity- 
Milk 
52.3 
Excreta 
578.6 
614.1 
115.8 
337.2 
9,469.1 
Protein . 
24.0 
36.0 
Fat 
37.7 
18,367.9 
407.2 
Balance 
7, 237. 1 
18, 984. 2 
18, 984. 2 
7, 325. 4 
7, 325. 4 
10,536.2 
10, 536. 2 
Cow 615: 
Water , 
13,851.8 
3.5 
3, 250. 5 
44.5 
17, 546. 5 
Dry matter irregularity- 
Milk 
94176" 
31.7 
Excreta 
874.3 
20.4 
40.6 
12, 920. 
617.8 
Protein 
7.2 
12.6 
42.6 
Fat 

42.9 
Balance... 
2,373.8 
17, 045. 9 
13, 855. 3 
13, 855. 3 
3,314.8 
3,314.8 
17,663.7 
17, 663. 7 
Cow 579: 
Water 
20, 772. 9 
17,086.4 
Dry matter irregularity- 
Milk 
8.0 
740.0 
57.0 
6.3 
19, 961. 6 
26.5 
641.6 
10.8 
65.8 
16,341.7 
Excreta 
Protein 
Fat 
Balance 
20, 772. 9 
20, 772. 9 
17, 086. 4 
17, 086. 4 
As already explained, during the calorimeter period the animal is 
assumed to have the same body temperature at the beginning and 
at the end of the experiment, so that no correction was made for 
change of temperature; but a heat correction is necessary for the 
change in live weight. Hence the character and quantity of this 
change must be determined, and a balance of the live weight of the 
animal has therefore been computed, which shows the total daily 
change in live weight due to various irregularities of excretion, etc., 
and the gain or loss of body tissue while the animal was in the calo- 
rimeter. The various items which enter into such a computation 
and the balances are given in Table 17. For the daily gain or loss 
of body protein and fat, the average figures as determined for the 
whole experimental period have been used, but the water is the 
