The recommended amount is as much as they want to eat! Dont put out vastly more than they will cope with,,as they will mess it up, but never let the feeder run empty.
You will know when they have had enough Smudger, when their little crop looks as if it can't take any more without exploding. Their digestive system isn't very efficient initially so they need to eat a lot to get anything. Mother hen will eat their poos early on as there is so much nutritional value left in them.
Ad lib feeding for chicks and growers. If they are out to free range at any stage of their lives, they spend a lot of time foraging for food = ad lib feeding.