I would shovel it out after sending them off to be butchered and the ammonia smell would only let me work about 10 minutes and the watering eyes and burning in the nose was horrible...30 chickens in a 10 X 10 room was nasty to clean up.. Pigs smell horrible even if kept clean. I think crap oozes from their pores. Nothing worse (except chicken coop cleaning)...
Chickens have no bladder so their poop is also full of urine and thats the ammonia smell. Yikes. Too strong to use as fertilizer unless it sat over the winter or it would burn the seedling..
Its not that noticable in a regular coop and our chickens were let out every day and just came in the coop to roost at night..
***30 chickens in a 10 X 10 room was nasty to clean up..****
Back in my youth, I had to clean chicken houses with a hand held scoop shovel. Those houses held about 10,000 chickens each and it was rough! $1.00 a manure spreader load. We cleaned only in the spring and summer as these old farmers kept the litter through the winter because of the heat it produced. It kept the fuel bills low. Hot, humid, covered with litter dust, and that ammonia smell, WOW!
Laying hen houses were worse as the litter there was slicker than owl snot, wet, and smelled just as bad!
Now, houses holding 40,000 are cleaned with tractors and front end loaders.