Should I totally cut out grain?

I have a hard keeper Arab gelding. I feed Purina Equine Senior which is not a hot feed and is great for maintaining weight. I also know many people who feed it to their hard keeper thoroughbreds. My vet recommends it for any adult horse. it is a complete feed, easily digested, prevents colic, and can even be mixed with water and fed as a mash. You should give it a try. My guy used to be prone to colic and hard to maintain weight on, but has done great on this feed. He also gets 24/7 free choice gr hay.