24 
BULLETIN 1372 ? U. S. DEPARTMENT OF AGRICULTURE 
The sires in Table 1 1 , ranked according to the size of the apparent 
correlation coefficients of their daughters with respect to butterfat 
yields, are divided in Table 12 into the three following groups: 
(1) Eight sires in group, from sire P, coefficient of correlation 
+ 0.90 to sire H, coefficient of correlation +0.48. 
(2) Eight sires in group, from sire I, coefficient of correlation 
+ 0.47, to sire V, coefficient of correlation +0.06. 
(3) Seven sires in group, from sire A, coefficient of correlation 
— 0.09, to sire N, coefficient of correlation —0.39. 
In each group, the sires are arranged in the order of their ranks as 
found in Table 5, and with each sire is given the average increase or 
decrease in pounds of butterfat. 
Table 12. — Sires divided into three groups according to correlation of daughters 
and dams, showing increase or decrease in butterfat production of daughters (each 
group in order of ranking) 
Group 1 
Group 2 
Group 3 
Sire 
Change 
in butter- 
fat pro- 
duction 
Sire 
Change 
in butter- 
fat pro- 
duction 
. Sire 
Change 
in butter- 
Letter 
Rank 
Letter 
Rank 
Letter 
Rank 
fat pro- 
duction 
D 
4 
6 
7 
10 
12 
17 
18 
20 
Pounds 
+128. 3 
+109. 
+92.4 
+44.8 
+73.9 
+13.2 
+6.4 
-10.4 
E 
1 
3 
8 
9 
11 
19 
21 
23 
Pounds 
+120. 4 
+138. 7 
+98.7 
+91.0 
+76.6 
-72.3 
-32.2 
-60.5 
B.- 
2 
5 
13 
14 
15 
16 
22 
Pounds 
+163. 8 
F 
C 
A 
+191. 
H 
G. 
N 
Q--_ 
+17.5 
L 
I 
—3.9 
K 
J 
T 
—51.3 

W 
M 
+30.6 
P._- 
s 
U 
—58. 2 
R 
V 
In Group 1, where the apparent correlation between daughters and 
dams with respect to butterfat yield is most marked, and where it 
might have been expected that the dams were exerting greater influ- 
ence than the sires on the producing capacity of the daughters, the 
sires are found to be fully as effective in increasing the producing 
capacity of their daughters as are the sires in Group 2, where appar- 
ently little correlation between the daughters and the dams exists, or 
in Group 3, where the correlation between daughters and dams is 
apparently negative. Indeed, some of the best and some of the 
poorest sires are found in each group. 
In this study the fact that the records of the daughters of a sire do 
or do not follow the relative size of the records of their respective dams 
seems to indicate nothing as to the relative influence of the sire and 
dams on the daughter's producing capacity. 
