My first horse, a common horse, after reaching level 50 has 40% speed, 11 stamina, and 26 capacity. So that means I apparently fed 26 times into capacity, 1 into stamina, and the rest which would be 22 times into speed. Tho that would mean my speed would have stopped at 37%, but its at 40% now. I really don't remember feeding into stamina at all either. I know for a fact that I fed 26 times into capacity because I wanted this to be a carry stuff horse.

I have a 2nd horse that I haven't really used but I am feeding. It is currently level 30. I have fed it exactly 20 times into stamina and thus have 40 stamina, and the rest is all going into speed. It is currently at 24% speed. Feeding it the last 20 times will put my horse at 44% speed, 40 stamina, 0 capacity.

My first horse looks like I fed it more than 49 times, and I am sure that I didn't somehow manage to do that. So do horses gain stats as they are used?