One reason not to feed hens free choice, all they want, if you are not using pellets or crumble, is because with mash or cracked grain feeds they will eat the parts they like and leave the rest.
They will leave a lot of fines and not get all the nutrients they need. If new food gets refilled they will wait for that new food to come and just pick out some and leave others so they never get a balanced diet.
If you feed only what they will eat all of, then you can be sure they will get all the nutrients they need and a balanced diet. A little less than up to 1/4 pound of feed per hen per day. And if they get out on some grass they will get more nutrients. If not you may go slightly above 1/4 lb. They need their stomachs full of nutrients and protein to be making and egg for 23-25 hours.
My hens prefer my non-GMO organic cracked grain and fermented cracked grain feed to the organic pellets I put out. So I can put them both out together and leave the pellets out free choice.
because when I put the cracked grain and ferment feed out for the day, they eat it all 1st. They eat all of the grain feed not just the parts they like leaving the rest and this way they get all the nutrients added onto the grain. And I don't leave it out free choice and have left over over night.
I can leave the pellets out all day so if they want more they can have them. Pellets are the only food I would leave out free choice and only if they eat all of their other grain feed first.
If they eat more of the pellets, because all the feed and nutrients are in each pellet, there is no way to pick and choose, they still get a balanced meal.
This way they do not over eat the grain as they might if it was left out free choice all day and get fat. Yes laying hens can eat too much grain and get fat which may reduce laying.
And this way there is no left over feed so you don't attract rats and birds to steal you feed and contaminate the runs. And if you do leave pellets out and don't put them up overnight you may want to get a rat proof feeder like a treadle feeder or some other pipe or tube feeder that limits pest access.
Most pellets instead of containing grain are full of junk, bran, husks, grain by products, screenings, etc. which are the powder and dust left over after the flour milling process. It is basically a waste product reclaimed and then sugar and corn syrup added to it and heated to make a feed pellet. I would not feed those to my hens.
No wonder hens come running to when people feed scratch, they are starving to death and want some real grain.
My hens don't come running to me when I go out because they are not starving; unless they find out I have some special treat for them I have tossed out on the ground or in feed tubs, coconut, pumpkin seeds, or some vegetable scraps, then they come.
So consider just putting out what they will eat that day in feed, other than pellets. And consider not feeding standard pellets. You can get some good organic ground up whole grain pellets, instead of middlings, millings, screenings, by-products, generic plant products, etc. with hydrogenated oils, sugar, corn sweet liquor, clay, and other heated and processed junk food. Its like trying to live off of Mc Donalds for you hens. READ THE FEED LABELS
Yes they will like the sugary junk food pellets as much as your kids like candy but that does not mean it is healthy. That is why my hens don't love the pellets I use. They nibble a few pieces here and there during the day.
The reason we have hens is to have good eggs and meat. Remember: You are what you eat ate!!
Its worth a few cents a dozen eggs to get the better food into them. And into you.