286 MANAGEMENT OF BREEDING STOCK 
them according to a well-established scale, and study the resulting 
fertility. Any great excess of infertility will probably be due to 
poor methods of breeding the birds, rather than to the relative 
number of males. 
Care During Mating Season.—A few points in the care of 
breeding birds during the breeding season must be specially borne 
in mind, and those which follow are of paramount importance. 
The style and type of the house should not be noticeably differ- 
ent from a good open-front laying house, but it should be so 
planned as to get an abundance of fresh air and sunlight. The 
extreme open front is probably the best for this purpose, as, not 
being used during cold weather, the birds need no protection from 
cold. Sunlight in the house is most essential. 
Plenty of room is needed. Breeding birds should never be 
crowded, for this will prevent some of them from getting sufficient 
exercise and sunlight, and will increase the tendency to disease and 
parasites. Moreover, it is impossible to study individual type and 
keep a careful watch on the health of the birds when too many are 
crowded into a pen of insufficient size. 
The birds in the breeding pen should be given plenty of exer- 
cise, and this can best be accomplished by feeding considerable 
grain in deep litter, or by varying the amount of mash which they 
eat, by the length of time which the hopper is left open, according to 
their body fat. Lack of exercise tends to increase deposition of 
fat, and this to deerease fertility. 
Feed for Breeding Hens.—The feed required by the breeding 
hen is almost identical with that of the laying hen, and can be 
supplied by giving a good laying ration. But a few important 
factors must be emphasized. The feed must contain an abundance 
of nutrients, since any lack of these will decrease the egg yield and 
the chances of fertility; it may also result in small-sized eggs, which 
is an important and undesirable feature. 
Protein in some form, preferably a high grade of beef scrap, 
has been shown by experiments to be invaluable for maintaining 
a high degree of fertility as well as for promoting a good egg yield. 
Just preceding the breeding season it is safe to give as much as 
fifteen or twenty per cent of beef scrap in the dry mash. But 
previous to this time, or during heavy winter production, forcing 
by this means is tabooed, as it is apt to lower vitality and to cause 
sterility or weak germs later i in the season. 
Green feed is a necessity. Experiments have shown that it 
