RELATION OF PRODUCTION TO INCOME FROM COWS. 
11 
for each successive large group. As production increased from 109 
pounds in the third group to 396 pounds in the ninth group, the re- 
turns for $1 expended for feed increased from $1.35 to $2.52, or 
almost doubled. In Group 3 the returns were only 35 cents above the 
cost of the feed, while in Group 9 the returns were $1.52 above the 
cost of the feed, or more than four times as much. It is also worthy 
of note that the feed cost per pound of butterfat was almost twice as 
high in Group 3 as in Group 9. 
Figure 5 shows graphically for the larger groups the relation of 
butterfat production to returns for $1 expended for feed as given in 
Table 4. 
Fig. 6. — One of the highest-producing herds in the Carroll County (Md.) cow-testing 
association. 
The curve shows that the returns for $1 expended for feed in- 
creased at a very rapid rate as production of butterfat increased. 
The larger returns for feed in the groups having high average pro- 
duction were due to better cows and better feeding. The relative 
influence of these two factors can not be determined because the 
groups whose average production was high were always fed more 
liberally than those whose average production was lower. 
Figure 7 shows graphically for the larger groups the relation be^ 
tween butterfat production and feed cost per pound of butterfat as 
given in Table 4. 
The curve shows a very rapid decrease in feed cost per pound of 
butterfat as production increased from 58 pounds to 396 pounds. 
From that point on the feed cost per pound of butterfat decreased 
more slowly. The figures indicate that from the standpoint of feed 
cost alone the dairyman should give close attention to the improve- 
