What does it mean?

I got a huge wrinkle ^^ I saw this word many times here, I tried to figure out by myself what does it mean but uncle Google didn't help. "CUBED" - the meaning of this word is very, very foggy for me and unacquaintance of it annoys me xD I read some descriptions of this word and it didn't seem to be bad, but here it has some negative undertone and I got confused as well. Can you guys help me and explain this word? The easiest way as it's possible xD

Cubed means horses getting treated with hay cubs on ev. Many players do it to horses under the age of 3, set the wrong discipline and convert back to have the lowest non-specialty stats on a horse. Cubing horses that are set to the correct discipline is generally looked down upon because it means that the horse's non-specialty stats are also increasing, making the horse do worse in shows.

Ah, okay, thanks ^^ I always convert my horses after peppermints and hay cubes :) I was wondering why people choose to give hay or sugar after setting the specialty, IMO it's illogical and completely ineffective.