Orpingtons and Brahmas are large bodied birds that don't have the greatest feed conversion rate. If you are going through 50# every 2 days for 65 birds, that's 6 oz each a day. Pretty average feed consumption. If it's 50# a day, than you have something helping. Chickens also only eat when it's light. If they have light 24/7 than they are eating 24/7. When you decrease their light to a more natural pattern of 12-15 hours a day, you should see a decrease in feed. Since eggs appear to be the goal here, I would suggest when you start looking at adding or replacing your layers, to add smaller bodied, better feed conversion layers.