The Breeding Herd 393 
BREEDING 
If more than five sows are to be kept in the herd, 
it will be more profitable to own a herd boar, while if 
less than five are to be kept, and if the service of a good 
boar may be procured from a neighbor, it will be less prof- 
itable to own the boar than to hire the service. Sows 
begin to come into heat when five or six months old, but 
should not be bred until they are at least eight months 
old, and fall-farrowed sows had best be a year old before 
being bred. Fall pigs do not develop so rapidly as spring 
pigs, so that at the same age they are not usually so large. 
Healthy sows will normally continue to come in heat every 
twenty-one days until they are bred. Several weeks be- 
fore the regular breeding season begins a record may be 
kept of the date at which the various sows come into heat. 
In this way one may know how many sows will be in heat 
at a certain time so that none need be missed and the 
boar may be handled more intelligently. If two or more 
sows are to come into heat at the same time, it is well 
to breed one of them as soon in the period of heat as 
possible, and not to breed the other until toward the close 
of the period. If small sows are to be bred to a large 
boar, a breeding crate is almost a necessity, for the in- 
juries to young sows will often amount to more than the 
price of a breeding crate. Likewise, the energies of the boar 
are conserved by the use of a crate. The one in Plate 
XVI was developed at the Oregon Experiment Station, 
and is as satisfactory as any. However, like fences for 
hog pastures, much is yet to be desired in the way of a 
satisfactory breeding crate. Not more than one sow a 
day should be bred to a boar and but one service should 
be allowed, if another sow is to be bred within a day or 
