Pellets are probably better more readily eaten. Powered supplements endup on bottom of feed pan uneaten. My horse will not eat powdered supplements doesn’t matter how there mixed in.
I’m not feeding any supplements to younger horse. 33 going to be 34 years old gets msm. He’s on tc senior and alfalfa hay. Done supplements and really saw absolutely no change so stopped buying them.
I’d be inclined to feed a good quality feed and see how horse does after 30 or so days on it. Chances are you’ll not need any supplements.
it’s called good marketing skills to make one think horse’s need whats being advertised.