Saddles on horses disappear

My horse saddles disappeared when I logged into my singleplayer world

I logged in and expected to find my horses with their saddles on.

Instead, none of my horses had saddles.

1. Place a saddle on a horse running a pre-13w21a snapshot.
2. Log out.
3. Update to 13w21a.
4. Log in.

The horse saddle will be gone.