<bread adds weight, but give no grain when giving it>
Spotted, perplexed as to what do you mean?? So far as I know, virtually all bread is MADE of grain?? I wouldn't advise much if any bread or other grain, esp wheat bread, esp if a horse had gut or metabolic issues.
Turmeric. Cheaper by the kilo from healthfood store than feed store. Probiotic unrefined sea salt... Oh wait, that's cheaper from feed store so I fill my kitchen jar from it!
Rosehips... Not from kitchen but old ladies gardens! Many whole fruits n veggies, from kitchen or garden. Herbs...
Gelatin is protein(I think couple diff sorts from memory) & one ingredient that can be beneficial for hoof growth. Like biotin is one ingredient. Like lysine is one other protein ingredient.
It Pays to look at the whole nutritional picture before adding supps willy nilly, as there are likely to be other nutrients out of whack too, and balance is also important - too much of a good thing is not good. You can't make a good cake without the right amounts of all ingredients.