You know the scene
Outside is nasty cold. The heater is working. The barn feels “warm” … but the litter starts to cake, the ammonia bite shows up at bird level, and health problems start creeping in. You end up fighting problems that look like they came out of nowhere.
This is usually not a bedding problem first. It’s a moisture-removal problem. When you can’t move water out of the building consistently, the litter becomes an over-used sponge and everybody pays for it.
Wet litter isn’t just annoying, it hits welfare and performance
In a controlled trial where litter moisture was deliberately increased (water sprayed on litter starting day 6), the “wet litter” groups ended up with 99% severe footpad lesions by day 36, versus 2% in the control groups. Average footpad lesion score was 2.0 vs 0.5 at day 36 (wet vs control).
That welfare hit came with performance and processing impacts. Over the full 0–37 day period, birds on wet litter finished 142 g lighter (1,948 g vs 2,090 g) and had a worse feed conversion (1.681 vs 1.614) (Reference 1).
A poultry veterinarian’s take
“The control of wet litter in broilers and more specifically low level enteritis has, over the last few years, become one of the most difficult and recurrent problems we face as poultry veterinarians.”
“The modern broiler seems too easily stressed and the early clinical sign of such stress is a more rapid gut passage of food material.”
— Richard Turner, MA Vet MB, MRCVS, International Poultry Production (Reference 2)
Moisture control wins because it fixes the root cause
Think of litter moisture like a simple balance sheet:
• Moisture coming in: bird output + drinker losses + wetter droppings (gut issues, feed changes)
• Moisture leaving: ventilation
When moisture leaving the building can’t keep up, litter condition takes the hit first. It is especially the case in winter, when everyone is tempted to cut ventilation to protect the fuel bill.
The winter trap: under-ventilating to save heat
Most wet-litter spirals start with a good intention: keep the barn warm and keep the propane bill from going sideways. So ventilation gets dialed back. Humidity climbs. Warm, humid air hits cold surfaces and condenses. Then litter goes from dry and loose to caked.
Higher litter moisture also feeds ammonia generation. USDA-ARS summarized research showing that increasing litter moisture increases ammonia emissions (Reference 3). Microbes break down nitrogen in manure faster when there’s moisture, which increases ammonia being released into the air.
Three moves that actually work
1) Stop free water before you chase ventilation
Start with the boring stuff, because it’s often the cheapest fix:
• Walk drinker lines and look for wet strips or shiny patches that never dry.
• Fix leaks immediately. One small drip across a line becomes a wet zone.
• If droppings are suddenly wet everywhere (not just near drinkers), don’t guess, call your vet/feed rep and treat it like a gut/management issue, not a bedding issue.
2) Bring in fresh air without losing heat.
Producers don’t get wet litter because they forgot ventilation. They get it because winter ventilation feels like throwing paid heat outside. Heat-recovery ventilation is one of the cleanest ways to break that trade-off. You move the air you need to pull moisture out, but you recover a big chunk of heat from the outgoing air stream.
With conventional inlets, you’re trying to balance a lot at once: opening/closing, static pressure, wind effects, and tightness. If things drift out of adjustment, you can end up with leaks, unstable pressure, and cold air dumping near the entry points. That creates drafty zones, bird stress, and wet spots that are hard to stay ahead of.
With a heat exchanger like the ESA-3000, air delivery is less dependent on “perfect inlet tuning.” The system uses fans to push air into the barn, so the incoming air has speed and throw. It penetrates and mixes instead of just slipping in and falling where it can.
3) Chase consistency at bird level
Wet litter often starts in the same spots: corners, end walls, and any area that doesn’t get consistent air movement. Don’t chase the average number on a controller screen, chase even conditions where the birds live.
How to check airflow without chasing bogus measurements
- Use a decent temp/RH meter at bird level and stabilize before believing the number.
- Watch trends (morning vs afternoon, after a cold snap, after litter top-dressing), not one random snapshot.
- Use your senses: condensation + caking + ammonia at bird height is a clear signal moisture isn’t leaving fast enough.
- A smoke test shows you exactly where air is moving (or not moving). It’s fast, visual, and it exposes dead zones that a thermostat will never tell you about.
Common winter mistakes that keep litter wet
- Cutting ventilation hard to save heat, then spending the next two weeks chasing caked litter.
- Overheating while humidity climbs (warm + wet air = condensation + wet litter).
- Waiting until the litter is already caked before reacting. Once it’s late, you’re always behind.
- Trusting a single cheap sensor reading instead of looking at trends + bird-level reality.
Want to know if a heat exchanger would help on your farm?
Call us at +1-855-573-2877 and we’ll look at your barn setup and help you figure out whether a heat-exchanger makes sense for your operation. If it’s a fit, we can even come out and run a smoke test as part of the evaluation.
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References
- de Jong, I.C., Gunnink, H., & van Harn, J. (2014). Wet litter not only induces footpad dermatitis but also reduces overall welfare, technical performance, and carcass yield in broiler chickens. Journal of Applied Poultry Research, 23(1), 51–58. https://doi.org/10.3382/japr.2013-00803
- Turner, R. (MA Vet MB, MRCVS). International Poultry Production, Volume 22, Number 4. (Article: wet litter / low level enteritis).
- USDA Agricultural Research Service (ARS). Poultry Litter Moisture Management to Reduce Ammonia (factsheet summarizing findings from Miles et al., 2011).
