Gowen: Transmission of Milk Yield 
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395 
Se a RS 
CROSSBRED NO. 12 
Offspring of the Holstein-Friesian and Guernsey parents shown on the opposite page. The general 
conformation of the body shows many points typical of the Guernsey mother; the size of the 
udder resembles the Holstein-Friesian parent. 
of this crossbred’s milk yielding quality with that of her parents. 
See the fourth graph in Fig. 14 for comparison 
While this crossbred’s milk 
record clearly follows the high milking parent, there is a tendency for the crossbred to be inter- 
mediate between the two lines. (Fig. 10.) 
may be duration of lactation as well as 
the daily quantity of milk yield. 
For the eight months lactation per- 
iod, Crossbred No. 1 produced on the 
average 4,161.3 pounds of milk. Her 
dam, Pauline Posch, produced 6026.3 
pounds of milk and her sire, Lakeland’s 
Poet's, potential milk yield was 3919.0 
pounds. Comparatively speaking, 
therefore, the crossbred cow was in- 
termediate between the two parents 
being 1865.0 pounds of milk less than the 
high line and 242.3 pounds more than 
the low line. The crossbred was con- 
sequently 7.7 times as near the low line 
of production as she was the high line. 
If we analyze the graph for her monthly 
milk yields as shown in Figure 14 
it is found that the Crossbred’s milk 
yield follows almost identically that 
of the low parent, Lakeland’s Poet. 
Only in the tenth month does it show 
any appreciable deviation from this 
low production. In this deviation ex- 
traneous causes enter, as explained 
above, in that the lactations are not of 
equal duration and the record of a cow 
is determined for whole monthly rec- 
ords only where these are available. 
This, of course, has the effect of making 
the end of the lactation record less re- 
liable than its beginning. For the 
tenth and eleventh month, the record 
of Crossbred No. 1 resembles the high 
parent although probably the resem- 
blance is not significant. 
The second graph of Figure 14 shows 
the milk production of Crossbred No. 2 
on a monthly basis. The significance 
of the three different lines is the same 
as that for the first graph of Fig. 14. 
Crossbred No. 2's record is unfortu- 
nately based on only one lactation rec- 
ord. The record for Canada’s Creusa 
