Gowen: Transmission of Milk Yield 309 
crossbred’s milk yield consequently re- 
sembles that of the high line 14.8 times 
as closely as it does the low line. 
The fifth graph in Fig. 14 represents 
the milk production of Crossbred No. 
15 and her parents, Lakeland’s Poet, 
Jersey; and Hearthbloom, Aberdeen 
Angus. The photographs of the ani- 
mals composing this mating are shown 
in the succeeding paper of this series. 
The graph for Crossbred No. 15’s milk 
production shows the same interme- 
diate yield as is shown in the first few 
months of lactation by the other pre- 
ceding crossbreds. 
The time of year for the commence- 
ment of the lactation has been favor- 
able to a medium to high yield for this 
crossbred as the months of calving were 
December (twice) and January (once). 
The total milk for the eight months 
period was 3493.0 pounds. The milk 
yield for the Aberdeen Angus mother 
was 1065.9 pounds and for the Jersey 
sire 3919.0 pounds. The crossbred 
cow was consequently 426.0 pounds of 
milk less than her high milk producing 
parent and 2427.1 pounds above her 
low milk producing parent. From 
these facts it is seen that this crossbred 
cow is 5.7 times as near the milk yield 
of her high milk yielding parent as she 
is her low yielding parent. 
The last graph in Fig. 14 gives the 
milk yields of Crossbred No. 16, her 
Jersey dam, College Ruth and her 
Aberdeen Angus sire, Kayan. The 
photographs cf the animals comprising 
this mating are shown in Figs. 11, 12 and 
13. This cow proved very difficult to 
settle for her second lactation. She has 
in fact lost nearly one year due to this 
cause. The milk production was some- 
what higher relatively for the second 
lactation than for the first lactation, 
although it did not continue longer in 
its duration. 
The milk production of Crossbred 
No. 16 is clearly intermediate between 
that of the high milk producing parent 
and the lower milk producing parent. 
The resemblance of the crossbred’s 
milk yield to the high line is very close 
for the first six months of lactation. 
From the sixth month to the end of 
the lactation the crossbred cow de- 
clined rapidly in her milk flow. 
Considering the whole of the eight 
months lactation Crossbred No. 16 
gave 3264.1 pounds of milk. Her pure 
bred Jersey parent gave 3581.5 pounds 
for the same period. The potential 
milk production of the sire was 1661.5 
pounds. It is easily seen from the 
diagram that the duration of the milk 
flow plays some part in this cross- 
bred’s milk yield. Thus up to the 
seventh month of lactation the cross- 
bred’s milk production was 2746.1 
pounds as against the milk production 
of her high producing dam of 2822.7 
pounds and of the low producing line 
of 1312.2 pounds. The difference be- 
tween the high milk producing line and 
the crossbred’s milk production for 
the eight months period was 317.4 
pounds. The difference of the milk 
production of the crossbred’s milk 
yield and the low potential milk pro- 
duction of her sire is 1602.6 pounds for 
the eight months period. The cross- 
bred consequently resembles the high 
producing parent 5.1 times as closely 
in its milk yield as it does the low pro- 
ducing parent. If we compare the 
milk yields for the first six months of 
lactation we find that the resemblance 
of the crossbred to the high line milk 
yields becomes 18.7 times as close as to 
the low line milk yield. 
Fig.15 represents the milk yield of 
six of the other later crossbred cows 
taken in the order of their birth. The 
milk yield for the first lactation is 
complete for the first five crossbreds. 
Four months of the second lactation are 
available for Crossbred No. 22; six 
months for Crossbred No. 26; a com- 
plete second lactation for Crossbred 
No. 27; two months for Crossbred No. 
29; and three months for Crossbred 
No. 37. In view of the fact mentioned 
at the beginning of this paper that the 
reliability of a cow's record increased 
as the number of lactations increases, 
it follows that without doubt the milk 
records of these crossbreds shown in 
Fig. 15 will be subject to some modifi- 
cation as the number of lactations in- 
crease. 
