DeepLoop Team · 2026-09-21
Broiler Litter and Air Quality: Wet Litter Is the Whole Game
Ammonia, hock burn, downgraded feet, a house that smells wrong - treat them as separate problems and you will chase each one forever. They are one problem seen from different angles: the litter got wet.
The <35% line
Ross says it in a single line - the primary cause of footpad dermatitis is wet and caked litter. Cobb puts the number on it: keep litter moisture below 35%. Under 35% it stays friable and keeps absorbing. Past it, it cakes, the pH climbs, and ammonia lifts off the pad into the air the birds breathe. The wet-litter to ammonia to footpad chain is one mechanism, and it starts at the floor.
Both breeders agree on the air
The two handbooks barely disagree on the air itself. Ammonia under 10 ppm, CO₂ under 3,000 ppm, CO under 10 ppm - Ross and Cobb, independently, land on the same limits. They differ only on how hard they put a number on humidity and dust. So the target is not in dispute. The moisture that decides whether you hit it is.
The wet-litter chain and the <35% moisture squeeze test, with litter depth by material - redrawn from Ross and Cobb.
Run the chain the other way
A Polish team ran the chain in reverse - hold the litter drier and watch the rest fall. They reared 480 Ross 308 broilers on sawdust: half the pens got the litter treated (zeolite mixed in at placement, effective microorganisms sprayed weekly) and half did not, everything else the same house. Keeping the litter drier improved the downstream measures the Monday reference chains together - evidence that the floor, not the air, is the lever.
From the litter-treatment study - drier litter through zeolite and microbial treatment improved the downstream air and footpad measures.
The floor the air comes off
The number under all of this is one nobody watches continuously: how wet the litter actually is, across the whole floor - not in the one handful someone squeezed by the wall. Wet litter comes from six places, and a single dry sample can hide a wet corner that is quietly caking. The air is a symptom; the floor it comes off is the cause.
Where this is heading
DeepLoop is working on the number under all of this - how wet the litter is, across the whole floor, continuously. Fix the floor and the air, the feet and the smell follow; watch only the air and you are treating the symptom.