12 
BULLETIN 1281, U. S. DEPARTMENT OF AGRICULTURE 
Table 6. — Daily weight of hair and scurf removed by brushing 
Cow No. 
Period 
Dry 
matter 
Nitrogen 
Carbon 
Organic 
matter 
as energy 
631 
615 
( I 
1 n 
III 
{ " 
i II 
Grams 
26.3 
18.7 
22.4 
22.7 
20.6 
18.8 
16.5 
Gravis 
1.88 
1.34 
1.60 
2.02 
1.84 
1.67 
1.29 
1.61 
Grams 
10.33 
7.34 
8.80 
9.99 
9.06 
8.27 
6.59 
Calories 
110.08 
78.27 
93.75 
107.53 
97.59 
579. _ 
89.06 
70.24 
20.6 
8.23 
87.70 
Total dry matter not fat has been computed according to the 
formula : 
sp. gr. — 1.0000 per cent fat n 
1000 ~~5 +U * 4 
To this the addition of the fat gives the total dry matter in the milk. 
METHANE 
The combustible gases escaping from the animal were determined 
in a continuous sample of air from the respiration-calorimeter cham- 
ber, which was first freed from carbon dioxide and water and then 
passed through a combustion tube, where by means of red-hot plati- 
nized kaolin the combustible gases were oxidized. The water and 
carbon dioxide thus formed were absorbed and weighed and from 
the weight of the carbon dioxide the methane was computed. The 
water determination, because of the long tubes and many rubber 
connections in the apparatus, is not considered so accurate as that 
of the carbon dioxide. The grams of methane per 100 grams of 
digestible carbohydrates (feed minus feces) have been computed, and 
these together with the other values for methane are recorded in 
Table 8. 
In view of the fact that methane is a product of fermentation, the 
total quantity in the separate periods as well as the amount per 100 
grams of digested carbohydrates was found to be remarkably uniform. 
The average amount per 100 grams of digestible carbohydrates for the 
eight periods of this experiment was 5.02 grams, whereas 4.5 is the 
general average from a large number of experiments made here and 
in Europe. The average amount of methane per day for the eight 
periods was 191.84 grams, or 267.6 liters under standard conditions. 
Table 7. — Amount, composition, and energy value of the daily milk 
Cow No. 
Period 
Weight 
Specific 
gravity 
Fat 
Dry 
matter 
Crude 
ash 
Total 
nitrogen 
Total 
carbon 
Energy 
value 
Grams 
Grams 
Grams 
Grams 
Grams 
Grams 
Grams 
Calories 
631. 
{ 
i 
5, 902. 5 
1. 0332 
335.3 
900.7 
43.4 
38.3 
483.9 
5, 378. 2 
ii 
812.8 
1. 0354 
43.3 
125.1 
7.8 
6.8 
70.1 
784. 1 
r 
i 
7, 227. 2 
1.0328 
334.6 
1, 004. 6 
46.7 
44.6 
542.4 
6, 020. 
615.. 
] 
ii 
7, 272. 8 
1. 0334 
352.7 
1, 040. 7 
47.8 
47.1 
556.7 
6, 278. 7 
1 
in 
7, 195. 
1. 0332 
343.2 
1,018.8 
46.7 
46.3 
550. 8 
6,157.0 
579.. 
{ 
i 
8,371.1 
1. 0330 
401.8 
1, 184. 5 
53.8 
49.2 
630. 6 
7, 023. 6 
ii 
8, 096. 7 
1. 0331 
383.0 
1, 140. 8 
51.7 
49.4 
598.3 
6, 749. 5 
