oh, that is a great idea. mice are easy to raise and breed. quails are another option too, also pigeon. actually, lizards too. there are thousands of little lizards living around me and they are so easy to trap, just set up a plastic container, even one of those tubs used to soak clothes in (i caught one today, even) and then keep them in some kind of enclosure, probably a clear plastic tub would do, and i even have a heat mat i can put under them, and then in parallel, catch a bunch of crickets and breed them up to feed the lizards.
i think overall, mice might be the easiest option tho.
i'm gonna think about this some more. it would be so easy to raise mice and just take them by the tail and smack them dead and drop them in his bowl. the only thing is my cat hasn't got his front canines anymore, but i think they cut up critters like mice mainly with their front incisors, the only cutting (as in, as opposed to tearing) teeth they have, and he still has all his incisors.
the advantage of mice is you can feed them on cheap seed feeds, even like the stuff they sell for birds, and just keep a big stash of tuna cans in reserve when the mice population is low and i can't feed him that.
thanks for the idea. this is what i'm gonna do when i see the opportunity. i may even do the mice soon, as it's not hard to get them at pet shops
feeding them what they eat in the wild is of course the best, and since he isn't out there picking up all kinds of parasites, it should result in substantial boosts in his immunity.