I remember reading somewhere that horses don't use protein to "bulk up" like humans do... Can't find the article online though and I can't find my stash of magazines!! Gah!!!
Personally, I would not add anything to his feed. He needs to walk and walk and walk in a frame and properly connected while pushing from behind to build muscle! Correct riding builds correct muscle. He is not going to magically bulk up because you change his feed.
Thanks Anabel! I was talking about this with my Coach and she said the same thing to me. She quoted an article Jim Wofford wrote for us Eventers saying how a proper Energized Walk at a long and low for a 1/2 hour a day will really help build up the topline and rump area.
I've been already doing alot of long and low on Nelson, so much - that's all he wants to do now. lol. I've been working on lifting his back up into my seat and asking for a forward, energized walk - while I remain on my 3 points of my seat, tall upper body, opened chest, soft carried hands to aid him.
I'll have to get some vid footage for you to see to tell if I am doing it right or not. It feels right, but what feels and what really is could be 2 completely different things.
I also contacted SmartPak, and explained the situation and after telling them about Nelson's history in Jan, and his age and condition now, they suggested this product: SmartGain 4 from SmartPak Equine SmartMuscle Mass from SmartPak Equine
They are sending me some samples of each to give it a try for Nelson.