17.2 hand, 12 year old WB/TB gelding that should weigh about 1500 lbs. He is in work 5 days/week doing upper level dressage. I spend all summer and part of the winter trying to keep him trim or getting weight off. However, he's come into spring the last 3 years with a dropped topline. He seems to loose topline at the same rate as the fat padding over his ribs - and it happens fast. I have about 2 weeks where I think he's almost at the weight I want and then the next week he doesn't look so good. This winter I had him on a RB instead of just a vitamin/mineral like previous years hoping that would help with this issue. Current feed is: Minimum 25 lbs hay per day - all grass hay currently (was 20 lbs grass and 5 lbs alfalfa until about 3 weeks ago) 3 lbs Gro-N-Win Grass RB Salt, MSM, Vitamin E, Biotin Things I have tried previously to put weight on: Rice bran Oil Sweet feed (for years I used to be able to throw him a handful of 12% sweet feed and he'd puff back up within a few weeks) I don't want to completely switch over his feed to something different (like a senior feed) as I'll likely have to switch him back to the RB within 2 months once he gains the weight back and the grass comes in. Also, I have a hard time getting him to eat powdered supplements and the barn won't wet/soak feed. Can anyone think of something else to add to his diet that might help with his weight and topline?