How do you make a mash for horses?

I need a recipe for mash. I can only find mash with bran in it. I refuse to use bran in any of my horses food unless I am told by a vet to do so. I know it takes like a year and tons of bran to create big head disease in a horse but I don't the bran to effect her bones even for one day. Do you know any recipes for mash without bran? Thank You