We get them but have restricted it to one 30 - 35kg bag a week as we only have 2 big adult pigs at the moment. We feed them 4-5 lbs of pig nuts each a day, so when we have the brwers grains, we take out a 1lb of nuts and give them a scoop (~1 lb) of brewers grains instead. Our last GOS did very well on this feeding regimes and were not at all fat, but we were very strict with their diet!
Most of the bag actually goes to our sheep who love the stuff and can't get enough of it. The pigs will eat it only after everything else is gone!