CARE OF YOUNG BREEDERS UNTIL MATURITY 289 
able time will show air cells of irregular shape, often on the side 
of the egg. The result is that the chick will occupy the wrong 
position in the shell, and in most instances a successful hatching 
is impossible. 
The length of time which the eggs are kept previous to hatch- 
ing bears an important relation to the hatch. Experiments show 
that the longer eggs are kept, regardless of the manner of keeping, 
the smaller will be the percentage of hatch. Eggs set in from two 
to five days will yield the highest percentage of chicks. Under 
average conditions it is not desirable to keep eggs for hatching 
longer than one week, but if they are carefully turned and kept 
at a temperature of 50° or below, satisfactory hatches may be 
obtained after keeping them even three weeks. 
Some Causes of Infertility.—Since infertility proves one of the 
greatest sources of loss, and probabiy depends in large measure 
upon the breeding stock and the mode of handling eggs, it is well 
to recognize a few of its common causes. They are here outlined 
as follows: 
Immature or extremely aged breeding stock, the former being 
the more common cause. 
Insufficient time between mating and the saving of eggs for 
hatching. 
Weakened vitality of the breeding stock 
Excessively fat breeders. 
Insufficient exercise. 
Lack of green feed. 
Lack of sufficient animal protein. 
Excess of females to one male. 
Unsuitable environment. 
The following are some of the causes of “ apparent infertility ”’ 
or death of the germs: (1) Low vitality of breeders; (2) keeping 
eggs at too high a temperature; (3) keeping eggs too long before 
incubation; (4) insufficient turning. 
Fertility is the one thing above all others which the breeder 
is seeking, especially after having mated his fowls for breeding 
purposes, usually at considerable expense. Want of attention to 
any of the above factors may result in a loss of this important 
requisite. 
Care of Young Breeders Until Maturity.—Birds hatched from 
high producing stock, and to be matured for breeding purposes, 
19 
