Sugar cubes

I just found out you get hay cubes for the riding school but where do you get sugar cubes from? thanks

you can get sugar cubes from riding school as well (though in pure stat gain, hay cubes are better).

Just remember that hay cubes raise random stats each day, so you don't want to feed them to a horse that's already in their proper specialization, or they won't show well. You either want to feed a horse hay cubes that's in a less popular specialization (for example, Dressage for Quarter Horses) and then switch them to their proper specialization (Western for Quarter Horses) before you breed them! The switch costs 10k, but will put all the stats in the right places (int and spd for Western).

If you already have horses in their proper specialization, it's better to feed them the treats that raise only their specialization stats.

Western - Int/Spd (Green Apple/Carrots)
Show Jumping - Agi/Spd (Yellow Apple/Carrots)
Dressage - Int/Agi (Green Apple/Yellow Apple)
Driving - Str/End (Red Apple/Turnip)
Racing - Spd/End (Carrot/Turnip)
Endurance - Int/End (Green Apple/Turnip)

For example, a western based horse wants stats in only Int and Spd, and the other stats don't come into account when showing. If they have high stats in the other areas (end/agi/str) they probably won't place in shows and so won't gain stats or earn any money!

Feel free to message me if you have any questions, as it can be a bit confusing in the beginning. c: