Heck, they could do a whole mix of flax, b-vitamins, magnesium, an all-around vit/mineral, plus the digestive aid all in one! Email and ask for a price quote. Here's what I would send:
Please quote me on the following custom mixes, all with added sweet flavoring for a picky horse. I want at least 2 oz of flax per-serving.
Glanzen 3 + 2g of added MagnesiumThe High Point Grass supplement has the b-complex in it and digestive supplements.
Glanzen 3 + 2g of Magnesium + Pro- & Prebiotics
High Point Grass + enough added Magnesium to make 2g + added flax (for 2oz of flax per-serving)
Glanzen 3 + Photo Finish + enough added Magnesium to make 2g