4 BULLETIN 923, IT. S. DEPAETMENT OF AGRICULTURE. 
of 22.4 cows, with an average annual production of 5,111 pounds 
of 3.9 per cent milk per cow. 
Out of each 100 cows during the two years, 58 freshened during 
the winter six months and 27 during the summer six months, while 
15 cows did not drop calves during the year. Thus there were 85 
calves each year for every 100 cows in the herds. During the first 
winter the cows were dry 2.T months (average) before dropping 
calves and 2.2 months during the second winter. In the first summer 
the cows were dry for 2.5 months before calving and 2.7 months 
during the second summer. The difference between the number of 
cows freshening in the winter and in the summer indicates that the 
cows were not bred to freshen uniformly throughout the year. The 
larger number of calves born during the winter does not mean that 
winter dairying was practiced to so great an extent as the number of 
cows freshening at that time would seem to indicate, for most of 
these cows freshened in the latter part of the winter and were really 
REQUIREMENTS FOR PRODUCING 100 POUNDS OF MILK. 
As the price of milk is generally based on 100-pound quantities, 
the requirements for milk production were based on this unit. The 
results are given in Table 1 and the credit for calves and manure in 
Table 2. 
Table 1. — Unit requirements, except charge for management, for producing 100 
pounds of milk in winter and in summer. 
Item. 
Winter. 
Average 
of two 
winters. 
Summer. 
Average 
of two 
summers. 
1916-17 
1917-18 
1917 
1918 
Feed: 
Purchased concentrates pounds. . 
Home-grown grains . . . .do 
29.0 
3.2 
30.2 
3.8 
29.6 
3.5 
7.2 
.5 
9.2 
.6 
8.1 
.6 
Total concentrates „ do 
32.2 
34.0 
33.1 
7.7 
9.8 
8.7 
Noncommercial roughage ....... do 
Commercial roughage: 
Carbohydrate hay do 
1.1 
108.7 
18.2 
1.2 
121.4 
9.4 
1.2 
114.7 
14.0 
3.4 
10. '4 
2.9 
.5 
18.2 
2.6 
2.1 
13.9 
2.7 
Total dry roughage do 
128.0 
132.0 
129.9 
16.7 
21.3 
18.7 
Silage and other succulent roughage 
pounds. . 
193.2 
189.2 
191.3 
19.9 
.09 
37.4 
.11 
27.8 
.10 
Bedding pounds. . 
Hauling and grinding concentrates 
dollars. . 
10.0 
12.5 
11.2 
0.020 
2.7 
.6 
0.005 
Labor: 
Human labor hours. . 
Horse labor do 
2.7 
.6 
2.7 
.5 
1.9 
.4 
2.1 
.3 
2.0 
.4 
Other costs: 
Building charges dollars. . 
Equipment charges and dairy supplies 
dollars. . 
Motor-truck charges do. . . . 
0.177 
.077 
0.174 
.097 
.003 
0.176 
.087 
.002 
0.128 
.056 
.005 
0.140 
.078 
.017 
0.133 
.066 
.610 
