Yes we feed a little rolled barley ,not too much ,don't replace all the oats with it , about a third. What you will find though is the crafty sods manage to eat their way round it taking all the best pickings , and leave a handful of dust in the bottom of the bucket, this is handed on to the chicks because it works out cheaper than chick crumbs, then as soon as the goats see it on the floor for the chickens they want it , but not in the bucket, contrary animals.
Brewers grains are harder to come by , even little micro breweries usualy get it taken away local farmers with big tractors by prior arrangement, If you have a neighbour that brews his own you might get lucky.