176 
record but do not have it because (1) 
some were used in small or grade herds 
and had little opportunity; (2) some 
are still too young to have many of 
their offspring tested; (3) some were 
too old at the time the advanced reg- 
istry system was inaugurated; (4) many 
breeders do not test, hence records of 
daughters are unknown; (5) some breed- 
ers secure better and some _ poorer 
records as a result of different methods 
of feeding, etc. However, it seems 
certain that, regardless of the fact that 
a few worthy sires might perchance be 
excluded for the above and other rea- 
sons, we do have here 32 proven sires 
whose offspring have increased and 
may be depended upon in the future 
to increase the average production of 
the breed. 
Up to December, 1915, there was a 
total of 254 sires who had produced one 
or more “equivalent of 600-pound”’ 
daughters. In other words, 32 sires, 
or only 12.6% of the total number of 
sires of 600 pound daughters, have 
three or more such daughters. This 
indicates that sires of great producing 
cows are relatively few in number. 
There were up to December, 1915, 
417 cows having records the equivalent 
of 600 pounds. The 32 sires listed 
above, produced 156 of these 417 cows. 
Therefore, we note that 12.6% of the 
sires of ‘600-pound”’ cows produced 
37.4% of those cows. 
Restating these facts in tabular form, 
we have the following data: 
222 sires produced 261 “equivalent 
of 600-pound”’ daughters, or 1.17 each. 
32 sires produced 156 ‘equivalent 
of 600-pound”’ daughters, or 4.87 each. 
Thus, the 32 sires above, were more 
than four times as prepotent as the 
remaining 222 sires of ‘600-pound”’ 
cows. 
When we observe that these 32 sires 
are only .092% of the male animals 
registered in the American Guernsey 
Herd Books and 2.20% of the 1,454 
sires of advanced register cows, the 
tremendous importance of the few 
strong sires, from the standpoint of 
improving the production of the breed, 
becomes quite apparent. Indeed, it 
can be safely assumed from the above 
The Journal of Heredity 
facts that less than one out of every 
thousand of the registered male animals 
will have a marked tendency to lift 
the production of the breed above the 
600 pound level. 
STRAIN OR FAMILY PREPOTENCY 
What has been said above refers more 
particularly to individual prepotency 
or the tendency of a sire to get produc- 
ing daughters. It is clear that a knowl- 
edge of the prepotent strains can only 
be gained by a study of the ancestry 
and descent of our great producing 
animals. When we study the pedigrees 
of the thirty-two sires in the above list, 
a noteworthy fact presents itself, 
namely, that they may nearly all be 
placed in a few groups according as 
they trace directly to some notable 
ancestor. 
These groups are as follows: 
GROUP A 
Related to May Rose II 8648 E. G. H. B. 
Charmante’s Rose King. 
Golden Noble II. 
Imp. King of the May. 
Imp. May Rose King. 
Imp. Golden Secret of Lilyvale. 
Jethro Bass. 
Dolly Dimple’s May King of Langwater. 
Lavaton. 
Beda’s May King. 
GROUP B 
Related to Masher R. G. A. S. 705 P. 5. 
Imp. Masher’s Sequel. 
Justinee’s Sequel of the Preel. 
Imp. Galaxy’s Sequel. 
Triple Champion 
King Masher. 
Charmante’s Rose King. 
Imp. Cora’s Governor of Chilmark. 
GROUP C 
Related to Governor of the Chene R. G. A. S. 
1297 BS: 
Imp. Governor I of the Chene. 
Imp. Holden IV. 
Imp. Cora’s Governor of Chilmark. 
King Masher. 
Imp. The Conqueror II. 
GROUP D 
Related to Imp. Glenwood Girl 1693 
Glenwood Main Stay 16th. 
Glenwood Stranford. 
Glenwood Reputation. 
Glenwood Boy of Haddon. 
Stranford’s Glenwood of Pinehurst. 
