Let me just check literally every horse I have ever gotten. Jumping horses hate me. EDIT: Lowest I have is 50%
Right though? Lowest I've got ( though not bred on my own, like duckne's, was just in a winners chest at MA ) is a 44, lol.
Your horse couldn't even jump a one block high fence. lol Just make sure it marries a Prancer and the kids will be just fine.
Who knows, if they pay attention and study hard, they could easily leap ahead of their classmates... ;]