If you are talking about Standardbreds then the pace is natural, though not all will pace. For example my mare is a Trotter, so she was raced with other Trotters. They didn't try to make her Pace. My sister is getting a mare who is a Pacer, so she raced in the Pacer classes. Her mare isn't home yet, and I really don't know how we are going to teach her that we want her to trot, and not pace all the time. So this thread will help us out.
Oh, and Pacers do know how to trot, but most that I have seen will choose to pace, especially if they have been on the track.
[COLOR=DarkRed]Well behaved women rarely make history!
Fpzipsdreammachine "Booty" 2006 AQHA mare