18 
BULLETIN 1372, U. S. DEPARTMENT OF AGRICULTURE 
PREPOTENCY OF THE SIRE 
The available records do not indicate whether a sire can be com- 
pletely prepotent in raising the production of his daughters, for the 
reason that comparatively few of the tested daughters of the various 
sires have dams that have been tested. Then, too, the lowest- 
producing daughters of a sire may not be tested, for it is doubtful 
whether some breeders would test a low-producing daughter of their 
herd sires. When the dam of a tested daughter does have a record, 
information is not available to show whether the dam's record was 
made under as favorable conditions as was the daughter's record. 
Although the information relative to the conditions under which the 
dams and daughters were tested is not available, and it is not known 
whether the poorer-producing daughters of these sires were tested, 
the information contained m Table 8 should be of interest. It 
shows the number of each of the 23 sires' daughters that increased and 
the number that decreased the yield of milk and butterfat, and the 
percentage of butterfat in the milk as compared with the yields of 
their dams. 
Table 8. — Number of each sire's tested daughters that . increased or decreased the 
milk and butterfat yield and the percentage of butterfat, as compared with their 
dams 
Sire 
Number 
of 
daughters 
with 
tested 
dams 
Milk yield 
Percentage of 
butterfat 
Total butterfat 
In- 
creased 
De- 
creased 
In- 
creased 
De- 
creased 
In- 
creased 
De- 
creased 
A 
5 
13 
12 
9 
6 
9 
7 
6 
6 
20 
6 
11 
6 
9 
6 
6 
11 
6 
7 
7 
7 
7 
16 
4 
11 
10 
7 
6 
7 
3 
5 
4 
11 
4 
9 
4 
6 
3 
1 
7 
3 
3 
4 
2 
1 
5 
1 
2 
2 
2 

2 
4 
1 
2 
9 
2 
2 
2 
4 
3 
5 
4 
3 
4 
3 
5 
6 
U 
4 
8 
7 
4 
4 
14 
4 
2 
1 
*15 
6 
2 
2 
13 
3 
5 
13 
2 
3 
1 
1 
5 
2 
1 
5 
5 
5 
2 
14 
3 
4 
5 
14 

9 
4 
15 
3 
1 
17 
4 
4 
6 
6 
2 
14 
4 
11 
9 
8 
6 
7 
5 
5 
4 
14 
5 
9 
4 
6 
4 
3 
8 
2 
2 
2 
1 
2 
2 
1 
B 
2 
0_. 
3 
D 
1 
E__ . . 
o 
F 
2 
G 
H 
2 
1 
I 
2 
J 
K . 
6 
1 
L 
2 
M . 
2 
N 
4 

2 
P .. 
3 
Q 
3 
R.. 
4 
S. 
5 
T. 
5 
u__ . 
6 
V 
5 
w 
14 
i One daughter had same test as dam. 
In Table 8, the second column gives the number of daughters of 
each sire that have yearly records and have dams with yearly records. 
In the column headed "Milk yield" is shown, on the left side, the 
number of daughters that made larger milk yields than their dams, 
and on the right side the number of daughters that made smaller 
yields than their dams. Similar comparisons are given in the columns 
headed "Percentage of butterfat" and "Total "butterfat." In the 
column headed "Percentage of butterfat," it will be noted that the 
number of daughters increasing and the number of daughters decreas- 
