Horse jump height and speed do not save into spawn eggs. Jump height might be fixable, provided my theory of Bukkit messing up is wrong. The same thing goes for speed, but since horse speed is not available through Bukkit API and only NMS, this is a lot more questionable.
Bukkit is telling me that some of my adult horses are babies in disguise. Not really kidding either. I would spawn in a horse, ride it, that was all fine, it did all the things adults can do that babies can't. But when captured, the spawn egg said the horse was a baby. More accurately, when SimpleEgg asks Bukkit if the horse is an adult, Bukkit says its a baby. So then SimpleEgg uses this when it spawns the horse, and what does Bukkit do with the instruction to spawn a horse and force it to be a baby (because I have no way to tell SimpleEgg if Bukkit is messing up or not)? Well, it spawns the horse, and the horse renders as an adult. But, the horse behaves as a child. All the adult functions of horses were disabled. The good news is that the horse will grow up, be it by time or feeding (though it will render as an adult the whole time).
