That does seem like a lot of feed. As Brighteyes said, it would be beneficial to break that up into at least 3 feedings per day.
I couldn't find the ingredient list or feeding recommendation for those feeds, but they seem like they're probably decent quality.
How's the quality of the pasture, and what type of hay are you feeding? It might be worthwhile to feed a higher energy hay (like orchard grass or alfalfa, or just a different cutting of what you can find easily) to allow you to cut back on the grain.