Let’s talk about maggot buckets

Hey y’all I’ve got a few questions about maggot buckets.
I’m wondering how long a bucket with chicken offal will produce maggots- how often do you need to add to them to continually produce maggots?
Because of gaps in processing times, offal or other dead meat are not always available, but Cow manure is readily available year round, so can you produce maggots with this system using only cow manure as an input?
Thanks, all!

Its upto the flies to do the work.
From google search "will maggots grow in manures"
“Manure is a natural substrate for fly larvae. ... Flies and manure have long enjoyed harmony. Female flies can ovulate up to 700 eggs during a life cycle, and the larvae thrive on decaying waste.12 Aug 2013

Do maggots eat manure?
Essentially, maggots are born from eggs directly into food waste, especially in moist environments, and live their lives by feeding upon food scraps and manure in that waste. ... These little guys eat and eat and eat, creating compost faster than you could imagine.19 Dec 2019

For the record, generally you wouldn't want to feed chicken-fed maggots back to chickens because a maggot isn't enough of a gap to prevent passing diseases. So I'd be looking for other critters to use as your growing medium - like road-kill, surplus racoon, any surplus rodents (mice, rats, squirrel, rabbits etc).

Where I live we've got both a feral rabbit problem and an invasive squirrel problem, and I'm really thinking that a maggot bucket might be very useful. Your questions about time span are of great interest to me.

It sounds like the link John C Daley quoted but didn't include, would give some good information about using manure as a feed-stock. Covering animal material with manure, might help control the smell, as that could become an issue if using dead animals - they do give off a unique smell!

I bury my chicken offal where the chickens won't get it and get the worms to turn it into useful soil.  I have read about it being put in buckets over a pond to feed fish.  Chicken - maggot - fish food is a safe gap disease wise, and theoretically, you could feed the fish back to the chickens with or without a maggot phase, but not too often or the eggs and meat of the chicken could start tasting fishy.

Could appropriate offal/scraps/roadkill not be frozen until required for the maggot bucket?

Flies lay their eggs (flystrike) on diseased (infected) and/or decomposing flesh (and other suitable decomposing matter) as this is the nutrition source for their hatching offspring, the maggots; much in the same way spiders leave a carcass for theirs.

For flies, I believe it is scent that attracts them to deposit eggs and/or warmth/heat allows the eggs to flourish.  In our climate  (BC, southern west coast, 🇨🇦) outdoor flies seem to vanish when the thermometer dips below 10C.  In cooler climes, for this to be a year long source,  a maggot bucket MAY need to be provided with some sort of heat source...  

Does anyone in cooler climes have successful maggot buckets in winter?  Does a barn environment provide adequate heat for year round flies and reliable maggot production?

I live in zone 3. There are no insects at all for 4 or 5 months of the year. We typically store food outside for 3 months because it is as cold, and often colder than the chest freezer.

I haven't even seen flies in a barn. I have seen the odd one in the house, but they go sort of dormant even if it's 72 degrees. It might be something to do with light levels as much as heat.

I wonder if you could use a hot bed in a Polytunnel for the carcasses and maggot growing - or one end of your polytunnel wired/sheeted off for this? Not fully thinking through atm, but a hot bed full if manure gives good heat for 3 months before needing to make another one or refill …

Make sure you have a saucer under your bucket to catch the maggots. They fall 24/7 and if allowed to burrow into soil, they pupate and hatch flies. I use a round plastic sled disc and tip the juice out periodically.