8 BULLETIN 106$, U. S. DEPARTMENT OE AGRICULTURE. 
figures by districts and by years in the relation of production to in- 
come over cost of feed shows that any change for one group of cows 
was always accompanied by a similar change for each of the other 
groups. For that reason the curve shown in figure 3 may be con- 
sidered as fairly representative for different years and for all sec- 
tions of the country. It does not follow, however, that the income 
over cost of feed will always be $26 for cows that produce 150 
pounds of butterfat and $106 for cows that produce 400 pounds of 
butterf at. The figures are relative, not absolute. The records were 
tabulated in many ways and always with the result that the groups 
of high-producing cows had a greatly increased average income 
over cost of feed as compared with the groups of low-producing 
cows. The figures showing the relation of butterfat to income gave 
much the same curve regardless of breed, age, weight, date of fresh- 
ening, or geographical location. 
Cow-testing-association records do not give labor costs and miscel- 
laneous expenses, but they do show which cows are paying for their 
feed and which are not. In one herd, records of which were tabu- 
lated, the poorest cow produced in one year only enough income 
from butterfat over cost of feed to buy a 2-eent postage stamp. To 
pay labor costs and miscellaneous expenses the owner had the 
manure, skim milk, and the calf. With better cows and more intel- 
ligent feeding he would have had much more. 
TWO HERDS COMPARED. 
In the Cheshire (N. EL) cow-testing association for the testing 
year 1917-18 the herd that produced the most milk per cow was 
highest in average production of butterfat, highest in cost of feed 
per cow, and averaged next to the highest in income over cost of 
feed. For the same year in the same association the herd that pro- 
duced the least milk per cow was lowest in average production of 
butterfat, lowest in average gross income, lacked 4 cents of being 
lowest in cost of feed per cow, and averaged lowest in income over 
cost of feed. The herd of greatest production per cow had an 
average income of $212 over cost of feed, while the other herd had 
an average income of $27 over cost of feed. It would require 78 
cows like those in the inferior herd to produce as much income over 
cost of feed as 10 cows like those in the other. 
BUTTERFAT AND COST OF FEED. 
The figures in Table 3 are from the same tabulation as those given 
in Table 2, and they show the relation between butterfat production 
and cost of feed per cow. 
