Equipment 377 
Because they require no glass and lighter framing, the 
colony houses are the less expensive in first cost. 
With the centralized house, the danger of disease 
spreading through the herd is greater, once it enters, than 
when colony houses are 
used. It should, there- 
fore, be planned with 
sanitation and easy dis- 
infection constantly in 
mind. Sanitation in- 
volves light, ventila- 
tion, cleanliness, and Fic. 33. — Typical “A” Hog House. 
pure-water supply. 
The method of ventilation depends on the climate. If 
the climate is severe, greater precaution will be neces- 
sary in admitting fresh air and permitting the exit of 
the stale air, while if the temperature is habitually 
higher, very little system is necessary in securing 
good ventilation. A hollow shaft leading from the 
floor through the roof will permit the exit of stale air 
from the bottom; and an intake under the eaves with 
a shaft opening just under the comb will admit fresh 
air from the top, which will minimize the draft on 
the pigs. Light may be secured by open space or by 
glass, depending on the climate. Since glass is expensive, 
it should be on the south side of the building, so that 
morning, noon, and afternoon rays all reach some part 
of the pig house where sunshine is needed. Any equip- 
ment used constantly isless expensive from the standpoint 
of results obtained than the same equipment used only 
a part of the time, and therefore greater expense is justified 
in case the glass is in the south whereit is used constantly. 
A plan with this end in view has been worked out by 
