Here is a summary on feeding. Feed like Starter, Grower, Layer and Allflock Contain everything your chicken needs for their entire life. Each one slightly different specific purpose. Like stated earlier. If hens are laying, and using other than layer feed, then add calcium in the form of oyster shells. It is good to have free choice oyster shells with layer feed as well. Source of grit as well. This compares to people eating lets say only oatmeal, and getting a handful of pills and vitamin and mineral supplements along side their bowl of oatmeal. Kind of a bland tasting diet. Where is my dessert !!! ??? But you get the idea.. You will live a long life. Giving chickens feed plus grains and scratch and table scrap leftovers , equals to people eating regular diets and enjoying life. Includes desserts and when some get the munchies. For various reasons. Free range ....... equals to free food. People equivalent to finding an orchard where you are allowed to eat all the fruit and not have to pay for it. Corn is good to feed to chickens , but not exclusively.. It even states it on every bag you buy. It is not complete in nutritional needs. Here is a test that anyone can do. Take 3 containers and fill one with Feed. Second with corn, Third, with a mix of various seeds. Now set your girls loose. I already know where all of them will be scrambling to.