394 Western Live-stock Management 
two. If no other sow is to come into heat within the 
time, a sow may be served at the beginning of the period 
of heat, and also near the close, for the period of heat 
is not always coincident with the discharge of the ova 
from the ovaries. After a sow is served, she should be im- 
mediately removed from other hogs. The boar should also 
be removed to his own pen if he does not serve her there, 
and should be shut off from other hogs, or at least from sows. 
Using the boar in different pensis likely to make him unruly. 
Three weeks after the sow is bred she should be tried again, 
or if she shows evidence of being in heat before three weeks 
is up, she should be re-bred. If the boar and sow are both 
in good healthy condition, there should be few returns. 
PREGNANT SOWS 
Usually if sows do not come in heat three weeks after 
being bred, they will not come into heat again until after 
farrowing, but occasionally a sow will pass a period of 
heat and then resume. It is therefore wise to try the sow 
for at least two periods after she has been bred. When 
pregnant, young sows should be kept gaining at the rate 
of about one pound a day during the gestation period, 
and old sows if in reasonably good flesh should gain from 
one-quarter to one-half pound a day during the pregnant 
period. With old sows, which are very thin when bred, 
a larger gain than a pound a day is desirable, but in no 
event should a sow be made so heavy that her feet be- 
come sore. 
The sow, during the pregnant period, requires feed con- 
taining an abundance of mineral and protein matter. In 
summer, if good pasture is available, heavy grain feed will 
not be required; in fact, some sows will make sufficient 
