SLAG! It's very safe for chickens or any other fowl/birds.
I was born in 1962 and lived in Birmingham Alabama which was known as the Pittsburgh of the south, a major steel producer. My great grandfather raised chickens for eggs and eating, he also raise ducks, geese, Guinea, turkeys and some guail. Being near the steel mills slag was his go to for driveway, barn and shed flooring material. He also used it for pathways from the house to each out building oh yes even the outhouse, I was sixteen and we still used the outhouse. Lol.
He chose the slag over sand, chert and gravel, not only it was cheaper but he said the chickens prefers it.
When I was very young up til the age of 10-11 my granddaddy had his driveway surfaced with slag, he also kept a large pile for fill ins, that pile was better than any sand, dirt or gravel pile. When slag got wet it would set up like concrete but remained digable and would flake away easily.
I could use a spoon or even my fingers to dig out caves, tunnels, foxholes, moats and roads for my plastic army men, I could/would play there for hours. Oh the best was when I got DAISY BB GUN. I would set up a fortress on and in the slag pile then set on a rock wall about 10-15 feet away and shoot the army men. Fun, fun for hours!
Anyways if you can get slag for your chickens do so.
My great grandfather said it helped with digestion and the hens produced more and larger eggs...
SLAAAAAG, ITS FOR CHICKENS!
