Ammonia control in livestock housing works by limiting where urine and manure release gas, then removing what forms on wet floors, bedding and pit surfaces. Ammonia appears wherever urea in urine meets urease from faecal bacteria, so the wet, organically loaded surfaces matter more than the air volume above them.
This is written for livestock producers, their integrators and the contractors who maintain housing equipment. The situations we are called into are usually a weaner house where the stock keeper has noticed the air at the slatted edge, or a complaint that is really about a manure store.
Product referenced in this article
Biological Deodorizer for Livestock Farms — application notes, specification table and document downloads for this range.
What actually produces the ammonia
The chemistry is simple. Mammalian urine carries urea. Urease, an enzyme abundant in faecal material and decomposing manure, converts that urea to ammonia and carbon dioxide. The reaction is fast with moisture, warmth and a surface to sit on, and slow when material dries out. Everything else follows from that.
It also explains why distribution inside a house is uneven. Urea comes from the urine stream, voided in predictable spots, so the highest generation is where dunging happens and urine collects: the dunging alley, the slatted area under a drinker, the wet zone under a nest or cage, and the pit lip. Air sampling at one height tells you little, because gas rises and mixes on the way.
Temperature and time compound it. A house held cool by minimum ventilation in winter keeps manure wet and slowly digests it, whereas the same house rested for a week dries out and releases less. That is why problems cluster in cold months and why a regime chosen in summer may not hold in January.
Why ammonia matters on a livestock unit
Ammonia is an irritant, and the respiratory tract is where it does its damage. The effect is cumulative rather than acute: a farm can run for years at a level nobody would call dangerous and still see reduced feed intake, uneven growth and more vet interventions. Young stock and animals already compromised by respiratory infection are the sensitive end. Loss of lung capacity also shows up at slaughter, so the cost appears well away from the cause.
The second reason to act is odour reaching people outside the unit. Ammonia is a significant part of the smell leaving a livestock building, and the component a neighbour most easily recognises. Treat the source and the complaint usually softens; but odour arriving at a boundary also carries other compounds, and we are careful not to imply a product removes them.
Which leaves measurement. Because people adapt to a smell so quickly, a note that the house seemed strong is useless as a control trigger. Handheld ammonia meters are inexpensive, and a fixed reading point read at the same time each day gives an actionable trend.
Why ventilation keeps disappointing
Ventilation is the first thing to check and should not be traded away. It sets the removal rate, controls humidity and temperature, and in a climate-controlled house it is why ammonia does not accumulate at dangerous levels. Any treatment works in a building that is also being aired properly, and a regime applied to an under-ventilated house is compensating for a design decision.
What ventilation cannot do is stop gas forming. Minimum rates are set to meet temperature and humidity targets in cold weather, and at those rates air exchange is lowest exactly when feed intake, water use and animal density are highest. Raising the rate in a cold spell costs heat and can create condensation, which then generates more odour. That trade-off is a daily operational decision treatment supports rather than removes.
Two management points are worth checking first. Where inlets or curtains are adjusted, re-verify the minimum rate, because an altered inlet pattern changes effective exchange at the same fan setting. And where a blocked drinker wets a floor continuously, that is a nitrogen leak no surface treatment removes.
Reducing generation and removing what forms
Two things can be worked on at once. The first is the nitrogen entering as urine, which responds to feed and water management and to keeping surfaces dry through drainage and slope. The second is what forms on wet organic surfaces, where biological and enzymatic preparations sit.
Biological preparations supply microorganisms with a carrier and nutrient system that lets them establish on wetted surfaces, in bedding and in the thin manure layer clinging to slats and pit walls. Because they establish rather than merely react, they keep working between applications, which suits the large continuous surfaces of a house. Performance depends on temperature, contact time and cleaning frequency.
Enzymatic preparations act on the urea-ammonia reaction itself instead of establishing a competing population. They respond faster and suit a defined, wetted point such as a drinker line, a wet corner of slats, or a dunging alley wall. Where the surface is cleaned regularly their effect does not persist, so they need more frequent application.
Our biological deodorizer for livestock farms is developed for this environment, where surfaces are wet, organically loaded and repeatedly disturbed. Where the house is on bedding rather than slats, bacteria for fermentation bedding treats the bedding as the reactive medium, and where manure is composted on site, livestock manure fermentation agent addresses that stage. A wet structural point washed every cycle suits an enzymatic deodorizer preparation. We are a National High-Tech Enterprise with 10+ granted patents and run our own fermentation pilot plant.
Working through the building
A livestock house is not one application problem, and treating it as a single volume is the most common reason results disappoint. The table is the sequence we work through, and why each location differs.
| Location | What drives ammonia there | What usually goes wrong |
|---|---|---|
| Dunging alley or pad | Concentrated urine and faeces, pooling at the lip | Dosed by building volume, not wet surface area |
| Slatted floor and pit walls | Clinging manure layer, slow air movement below | Scrape-out removes biomass as fast as it establishes |
| Drinker and feeder line | Continuous wetting, spilled water carrying nitrogen | Leak or mis-set height left in place |
| Bedding zone | Warm, wet organic surface, large active area | Blamed on manure when bedding is the source |
| Manure pit and store | Large emission surface, often outside the envelope | Odour blamed on the house rather than the store |
| Inlet and curtain area | Air drawn across wet surfaces, cold-air inflow | Inlets changed without re-checking minimum ventilation |
Dosage is set against surface area, temperature range and cleaning frequency, not animal numbers. We do not publish one dosage table, because a figure that suits a slatted finishing house will be wrong for a dunging alley. Typical figures are given in the quotation once locations are agreed.
Limits, safety and what this cannot do
Ammonia is toxic at concentration, and no treatment regime changes the safety requirements of a livestock building. Entry into a manure pit or dunging alley still follows the site's own procedure, including gas monitoring and rescue provision, and treatment is applied after that procedure is complete, not as a substitute. Concentrations rise fast in a slurry store, the one place where we would rather a contractor did not improvise.
We are equally direct about what treatment cannot do. It does not correct a leaking drinker, an undersized pit, or a house whose minimum ventilation was never set for its climate, and it does not remove odour from an uncovered slurry store at a boundary. Where the cause is that kind of problem, the answer is engineering work.
Monitoring whether it is working
Measurement decides this, and the method is simple. One fixed reading point per house, at stock level in the breathing zone, read with the same meter at the same time of day over one production cycle including a clean-out. Readings taken while a building is washed are meaningless, so note what was happening on the sheet.
Watch the response to change rather than any single number. Did levels fall after the regime started, hold through a cold spell when minimum ventilation was lowest, and climb again after a clean-out or bedding change? Two or three such events tell you more than a season of readings, and a short log identifies which location is driving the result.
What to send us for a specification
Send the species and building type, number and age of animals, floor and pit arrangement, bedding system, current ventilation rates, temperature and humidity ranges, wet surface area, and how often the building is washed. If manure is composted on site, that arrangement is useful too.
We reply with a proposed regime and dosage by location, an indicative price and the specification sheet. We are ISO9001, ISO14001 and ISO45001 certified.
Frequently asked questions
- What causes ammonia in pig and poultry housing?
- Ammonia is released when urea in urine is broken down by urease enzymes, most of which come from faecal bacteria and faecal material. Wherever urine and faeces mix in a warm, wet environment the reaction speeds up. That means the slatted floor gap, the dunging alley, the bedding surface, the drinking-water spill line and the manure pit are the places where it forms, rather than any single fixed point.
- Is ventilation alone enough to control ammonia in a livestock building?
- No. Ventilation is necessary in every climate-controlled house and is the first control to correct, but it dilutes and carries away gas rather than stopping it forming. Minimum ventilation rates set for temperature and humidity often leave a house under-ventilated during cold weather, which is exactly when stock density, feed intake and water use are highest and generation peaks.
- Does ammonia harm animal health and growth?
- It is a recognised irritant. Sustained exposure at levels above what workers can smell reliably can affect the respiratory tract, reduce feed intake and growth performance, and increase the work of breathing in young stock. Because people also stop detecting it early, using smell as the trigger for control is unreliable on farms where staff are exposed every day.
- What is the difference between biological and enzymatic ammonia control?
- Biological preparations supply microorganisms that establish on wetted surfaces and in bedding, competing with the organisms that drive urea breakdown, so their effect persists between applications. Enzymatic preparations act directly on the urea-ammonia reaction and respond faster but do not establish a population, so they need contact with the source and more regular reapplication.
- Can ammonia control reduce odour complaints from neighbours?
- It helps, since ammonia is a significant part of the smell leaving a livestock building, but odour reaching a neighbour also carries other compounds that a specific treatment does not address. Where the complaint originates, the fix is usually a combination of source reduction, correct air exchange and the handling and storage of manure outside the building.
- What information do you need to specify a product and dosage?
- Species and building type, number and age of animals, floor and pit arrangement, bedding system if any, the current minimum and maximum ventilation rates, temperature and humidity ranges, the surface area to be treated, where readings are taken and whether there is a manure storage or compositing step on site. With that we can quote a dosage by area and an application regime rather than a generic figure.