Hmm, can he have grains if they don't have molasses in them?
Only reason I ask is that there is a "natural" cattle range cube that would be very similar to what I use as treats for my horses. The only difference is, the ones I buy have a bit of molasses in them and the natural ones don't. The main ingredient in these cubes is grain by-products.
Basically, they are just a compact roughage cube, but my horses adore them.
This is what I feed Super 20% Range Cube - Shawnee Milling
And these are the "natural" ones without the molasses. They are the second one down Shawnee Milling Company