[maine-iac7]

I had a friend in Utah that heated his chicken houses - 30,000 chickens - with a chicken-poop furnace - back in the early 70’s.

[BwanaNdege]

A South African pig farmer, John Fry, used a bio-digester to convert his pig manure into methane gas which he used to fuel his Diesel electric generator. This was back in the 1970’s.

http://journeytoforever.org/biofuel_library/MethaneDigesters/MDToC.html

[Rebelbase]

“a chicken-poop furnace”

The smell must have been horrendous.