It can be difficult to determine if your gilt or sow is in heat.  If you have a boar and he’s in the mood, he’ll let you know.  If not, you can miss the signs.

Here’s a picture of some lady parts in heat…

Notice that her “pointer” is swollen and puffy.  You’ll see this when she’s in heat.

Notice that her tail is straight and out of the way?  This is because there’s a boar nearby and he’s putting off his “I’m ready” scent.  When you artificially inseminate, you’ll need a bottle of boar scent to spray.  This queues the girl that it’s time to be mounted.

A sow’s or gilt’s heat cycle will a full day at minimum and often up to 48 hours.  She won’t be ready to go immediately when the cycle starts.

You can tell she’s ready by pressing on her back.  If she moves away, she’s not ready.  If she stands still, she’s ready.

Our boars make a low, rolling grunt sound when a girl is in heat.  The sound is a lot like an engine revving.

It’s not exact, but 3 months, 3 weeks and 3 days later you can expect some piglets.