252 PRACTICE OF POULTRY BREEDING 
at any time, a lack of constitutional vigor will never prove profit- 
able for any purpose. 
Further possibilities in selection are discussed under the sub- 
ject of breeding for definite purposes. 
BREEDING FOR EGG PRODUCTION. 
It is probable that more poultrymen are endeavoring to increase 
the egg-producing qualities of their birds indirectly by breeding 
and selection than are attempting to improve all other qualities 
combined. This is due to the fact that egg production represents 
a direct money return which, under farming conditions, is the 
one factor of greatest definite value. 
The Poultry Department of Cornell University has been a 
pioneer in advocating the selection and breeding for egg production. 
As a result of its investigations and teachings, the following rules 
or guides have been laid down, and success will follow their use. 
The rules follow and should be kept in mind when breeding for 
egg production: (1) Keep only pure-bred birds; (2) breed from 
heavy producers and persistent layers; (3) breed from mature birds; 
(4) practice line breeding; (5) breed from early-preducing pullets; 
(6) breed from late molters; (7) breed from heavy eaters; (8) breed 
from early risers and late retirers; (9) practice proper management. 
Keep pure-bred birds of one well-established egg breed. They 
have proved to be the most economical producers of market eggs, 
laying the greatest quantity of excellent quality, while the feed 
consumed is utilized to better advantage than in other types. 
There is also greater uniformity in the shape, size, and color of 
the eggs, and a greater demand and selling value in general and 
special markets. The uniformity with which pure-bred birds may 
be bred and developed for a given purpose, such as egg production, 
is much greater than with mixed or impure stock. 
Breed from Heavy Producers.—This is one of the leading rules 
in breeding for egg production. The average productive power 
of the progeny may be greatly increased. This can only be accu- 
rately carried on by the use of the trap nest and by special matings 
for breeding purposes. The most persistent layers are those which 
begin to lay early in the fall (October or November) and continue 
to lay regularly. throughout the winter and spring months, also 
laying well during the summer, and which, after undergoing a 
quick, complete molt, begin again to lay in the early fall of the 
following year. In selecting a breeder it is not safe to take the 
