Dec. 3, 1917 
Fatness of Cattle and Feed Utilization 
455 
rations of periods 2 and 3 than ou the lighter rations, and that they were 
on the average a little greater in the fattened than in tha unfattened 
animal. 
Table VI .—Percentage losses in urine 
Period No. 
Percentage of total— 
Percentage of digestible— 
Nitrogen. 
Carbon. 
Energy.® 
Nitrogen. 
Carbon. 
Energy.® 
71. 04 
5 - 2 5 
5* 16 
94-53 
6. 89 
6. 83 
61. 54 
4-58 
4.55 
86.26 
6.19 
6. 20 
3 . 
61. 84 
4. 8l 
4 * 9 1 
88. ^6 
6.45 
6. 62 
4 .. 
80. 51 
5-69 
5.38 
i° 7 - 75 
7-47 
7.11 
a Corrected to N equilibrium. 
combustible gases 
Fries (5) has shown that the large number of respiration experiments 
executed here during the last 15 years seem to demonstrate beyond ques¬ 
tion that the fermentation gases given off by cattle on normal rations 
have substantially the composition of methane. The results of the 
present trials (Appendix, Table 5) are entirely in accord with those of 
earlier ones and show a ratio of hydrogen to carbon corresponding sub¬ 
stantially with that of methane (1: 2.976). The slight deficiency of hydro¬ 
gen in most cases we ascribe to the difficulty of securing complete oxida¬ 
tion of the last traces of this element. Table VII shows the ratio of 
hydrogen to carbon and the computed amounts of methane, both per head 
and per 100 parts of digestible carbohydrates. In accord with our earlier 
results ( 3 , 4) the extent of the fermentation of the carbohydrates, as 
measured by the methane excretion, was decidedly less on the heavier 
than on the lighter rations. The range of the results is substantially the 
same as in previous experiments on similar rations, particularly those in 
which alfalfa hay was used. 
Table VII .—Production of combustible gases 
Period No. 
Ratio of 
hydrogen 
to carbon. 
Methane computed 
from carbon. 
Total per 
day and 
head. 
Per 100 
Gms. of 
digested 
carbohy¬ 
drates.® 
1:2. 970 
1:3. 063 
1:3. OIO 
1:3.048 
Gm. 
137-3 
206. 0 
215.8 
154.0 
Gm. 
5-2 
3.8 
3-7 
5 -o 
O .. 
® Crude fiber plus nitrogen-free extract. 
