Make sure you have several months of chicken food if you supplement their ‘free rangeness’.
Ditto pet food.
No problem on grain-type chicken food. Lots of local sources / producers / processors. Some deliver, can hit outside of 50 lb. bag with heat gun or disinfectant if paranoid. Plus our & Mom’s scraps, and if worse comes to worse, Asian Carp.* Only problem might be “Layer Pellets” - not sure where they are processed, but, this being an agricultural area with lots of “farm stores” (Tractor Supply, Rural King, etc.), not too worried. Might not even need, really - can smash up egg shells and feed ‘em fish for protein in non-buggy seasons.
Our cat is a good mouser, even takes down a squirrel now and then. Doesn’t even eat half of what she deposits on back porch. Might want to get 6 months extra flea treatment, tho’!
*Actually Asian Carp is an excellent food source for chickens and the cat, just need time to obtain “free”. Local processor (Chinese lady!) is up to over $5 / lb. from their retail operation - too pricey! Tasty if prepared well & low contaminants for all, but have not yet tried it in a pressure cooker to cook out the annoying-to-humans numerous small bones.