256 PRACTICE OF POULTRY BREEDING 
3. The use of pullets instead of hens for breeding will lower vigor 
by producing progeny from immature parents. 
4. Too heavy feeding during the fail and winter with the object 
of increasing production. Under normal conditions the fowl is 
allowed a part of the year in which to rest and store up energy 
for future seasons of heavy production, and it will be found that 
forced feeding and heavy production are antagonistic to the 
highest fertility and greatest degree of vigor in the offspring. It 
is well, therefore, at as early a date as possible, to pick out all the 
adults which are desirable for use as breeders, and give them time 
to store up energy and physical strength. 
5. Excessive Crowding or Congesting of Breeding Stock—The 
modern intensive system of handling poultry is responsible for 
much of the present low vitality. Where it is desirable to raise 
future economic producers, it should be the policy to handle the 
breeding fowls on extensive farms rather than on intensive produc- 
ing poultry plants. Both young stock and breeders have more 
vigor when raised on land used for other purposes, as fruit 
growing, grass, and grain crops that are being raised mostly for 
pasture and green forage. 
6. Lack of exercise for breeding stock is another direct cause of 
low fertility and subsequent low vitality. 
7. Carelessness and improper methods of hatching and rearing 
chicks give bad results. 
8. Failure to select breeding stock with superior physical vigor. 
If the desire is to increase or even maintain a high degree of vitality 
this selection is paramount. 
The following signs of high vitality have been listed by Rice 
and Rogers and should be applied when making selection for vigor: 
The actions and movements of fowls probably best indicate their 
physical condition. The physically weak are inactive and dull, and 
more likely to sit than to stand. They do not range to any extent 
in search of forage, nor do they scratch in search of feed. They 
are longest on the perch, possibly spending the entire day there. 
The loudness and frequency of the crow of the male, and the 
cackle of the female, are indications of physical strength and 
superiority. The weak fowls seldom crow or sing. 
There are certain body signs which indicate lack of vigor in a 
fowl; as, for instance, long neck, thin beak, narrow head, a long, 
slender body, long legs and thighs, or a stilted appearance, while 
the reverse is true of vigorous birds. 
