will teff hay make my horse "hot"

i have a horse that if you feed grain or alfalfa he goes absolutely nuts full of energy, and my beginner safe 20 year horse turns into a bronc that many experienced riders look at and say "I'm not riding him today"

i was told that the high protein in alfalfa is what makes my horse hot, i have been reading that teff hay has low sugar and carbs and how good it is but it says that teff has a decent amount of protein. does anyone have a hot horse that eats teff and is fine with it?

will teff hay make my horse "hot"