Hello!
Old post, I know, but someone else might be looking for ways to cut their feed costs.
1. You got the anser already. Free ranging chickens will eat maggots, worms and whatever small bugs and stuff they find.
2. House flies will work. But, if you have chickens, you probably have Blue and/or Green Bottle flies/Blow flies also. They are about twice the size of a house fly and the colour is black with a blue or green metallic shine. They feast on dead meat and poop/manure. These flies are readily available anywhere there is manure or a dead carcass. No need to buy special flies.
3. Farming maggots: You need two big plastic buckets. When fitted into each other it should leave a space between the bottoms of at least 1-2 inches. A lid on the top bucket.
Bottom bucket: Make tiny holes around the side about 1/2 to 1 inch from the bottom. I mean tiny, like with a heated needle, or make small cuts with a crafts scalpel or simular. Last way is best, makes tiny slits in the plastic for air ventilation and maggots can't crawl out.
Top bucket: Make lots of holes in the bottom about 1/2 inch. Drill or cut with a fine knife. Also make same size holes around the side about 1 inch from the top. Here is where the flies will come in to lay eggs.
Something to elevate the fly food of the bottom: Some kind of grid, very simple, just a few small wood planks laid crosswise and screwed together will be fine. Or anything grid-like. You will bait the bucket with dead meat such as road kill, guts from hunted animal or fish. You can also "spice" the carcass with chicken poop to make it even more attractive to the flies.
Setup: Place the bucket with holes inside the other bucket. Sprinkle some fine saw dust on the bottom (optional, but I find the maggots can crawl out of the holes easier if there is a little saw dust in the buckets). Place the grid over the holes and your meat scaps on top. Not too much, perhaps one rabbit in a 4 gallon bucket. Somewhere around 2 inches. If it's too much meat there will be wet stuff covering the holes. Cut whole animals in a few smaller bits so the flies can find the meat easy and lay eggs on it.
Close the lid. Put the farm outside away from direct sun, but warm. Maybe a simple rain shelter if it's pouring. Wait a few days. Check the bottom bucket for maggots every few days. Harvest with a spoon and feed to your chickens in a bowl with straight/high egdes so the maggots don't crawl away so fast.
Replace the fly food as needed, dig the remnants down in your compost. You can also freeze the maggots for later.
This setup uses the maggots natural instincts: The new hatched maggots will feed on the meat until they are big enough. Then they want to crawl away from the moist meat to a dryer place to burrow and pupate. This is when they fall through the bottom holes. Small larvae will usually stay in the meat and feed until they are big. This way flies can continue to lay eggs until the food source is depleated. And larvae will emerge continuesly as long as they have food.
This is how I get free protein treats to complement my chickens regular feed. It's smelly, so place it far away from your house/patio, etc.
The cost is almost zero if you use scrap materials and stuff laying around. Road kill is free, keep your eyes open when driving/walking/biking around in your area.
And if you decide it's not for you, "closing" the farm and cleaning everything away is easy. Just dig down all organic matter and discard the buckets.
Some people have only the top bucket with holes, grid and lid. They hang it in their chickens coop and place a large board on the ground so when the maggots crawl out they fall on the board for the chickens to eat. This is less work, but maggots falling out during the night will crawl away and burrow to pupate.
Good luck!
