We have our own chickens in our freezer, and I much prefer either the heritage type birds, which I order straight run, and eat extra cockerels, or the Freedom Ranger type of meat birds, who run around like normal chickens. Both take longer to grow, and so cost more to grow, and don't come out...
Welcome!
It's hard/ impossible to overcome genetics completely, and these birds are all meant to go to the freezer by eight weeks of age or so.
Do you eat chicken? Your birds are having a much better life than any of those at the supermarket!
Do feed them a complete diet, not scratch (bad...