At first I did not understand your wording. Then I googled brewers grain, that cleared it up. I never knew this existed, but it sounds like it would be very good for a feeder. I don't see how any self respecting hog could not be all over this.
It appears like you have used it.
Where were you able to purchase it?
Would this work in a timed feeder?
I think you are on to something.
Thanks for the post.