I just kept feeders filled for mine and let them eat for 12 hours after the 2nd week. How much they ate I don't know as I didn't keep track of the feed consumed. I had a pen of 25 and when a 50 lb bag of 18% was over half gone I would just buy another one. At the normal butchering age I switched them to layer feed and give just enough to maintain them and they get to free range during the day.