I have the Orlov Trotter pb, which is of medium build.They are great in Harness Racing & Jumping ,but fail epicly at Fox-hunting.

I cannot blame their stats, as their bc is Ex/Su/Ph/Ex and they roll easily to Am/Su/In/Ex during training.So, I suppose that their build is the problem.
Among my 8 foundations, there is a pair of slim build.Their offspring is also slim ,but this is where the party ends.From the confy trial I can see that my slim pairs are critically slim, so when I breed them they produce medium foals.
I know that Driving affects build ,but pushes it to the drafty side.So, I roll-preped a pair using Speed Lap, Track Endurance, Obstacle & Gaited & rolled with Arena Enrage. Guess what?Medium foals.

Any suggestions on how to starve my fat cows?
