I would go with Alfalfa pellets, a vitamin supplement, flax meal or stabilized rice bran (most feed stores have it) or "Omega Horseshine", and Tri-Amino
(optional, but it will help muscle development and growth). That should be a nice "rounded" diet for her, with most of the nutrient requirements met.
I would feed 1/2 to 1 scoop using a 3qt feed scoop of the alfalfa pellets. You want 1/2 cup of the flax or rice bran. Go with recommended levels of the vitamin supplement and tri-amino.
For vitamin supplements, I would recommend Smart Vite Maintenance Grass
(has the aminos, so you wouldn't need tri-amino), EquiBase Grass
, Select II
, Balance II
, or Augment
(best starting first).
I feed my horses a similar diet and they do VERY well on it! I have my vitamin custom blended by horsetech.com
, so I can get the vitamins, minerals, amino acids, and flax all in one bucket. It costs me $0.87 per day, which is actually cheaper than buying it all separate. I use a little water or apple cider vinegar to mix it in with the alfalfa pellets. If you call them, they can custom blend you a supplement based on your horse's age and feed. I'd request high levels of the amino acids from tri-amino, plus at least 2 oz of flax per-serving, and some extra biotin (I get 10 mg per-serving).