Clinoptilolite for Poultry Litter Ammonia Control

Q: By what mechanism does clinoptilolite reduce ammonia when added to poultry house litter?

When uric acid in poultry manure breaks down in the litter, ammonium (NH₄⁺) and ammonia (NH₃) reach an equilibrium. Clinoptilolite has a negatively charged framework and a cation exchange capacity (CEC) of 1.6–2.0 meq/g, so it captures the cationic NH₄⁺ within its framework, reducing the amount that volatilizes as gaseous NH₃. Because ammonium is a cation, it is adsorbed by natural clinoptilolite without any separate modification, and an ammonium adsorption capacity of about 21 mg/g has been reported in model solutions. Nakaue et al. (1981) and Karamanlis et al. (2008) reported improvements in ammonia and house environment under poultry house and litter conditions.

Q: Does it help with broiler footpad dermatitis and respiratory health?

High ammonia concentrations in the poultry house, together with wet litter, cause footpad dermatitis, hock burns, and mucosal and respiratory irritation. Mixing clinoptilolite into the litter adsorbs both moisture and NH₄⁺, keeping the litter drier and providing a supporting effect that lowers NH₃ volatilization (Nakaue et al. 1981). However, ventilation, stocking density, and watering-line management are the primary variables, and zeolite is a supplementary material that does not replace them.

Q: How much should be applied per m² of litter, or per flock cycle?

In field practice, surface application to litter is typically considered in the range of 5–10% of litter weight (or about 0.5–1 kg/m²), divided into mixing into fresh litter before placement and additional surface spreading during the growing period. The 14×40 mesh granule is suited to litter surface spreading and mixing, while the 100-mesh powder is suited to localized use given dust concerns. The exact amount should be calibrated through a pilot according to litter type, stocking density, and ventilation.

Q: Is the regulatory labeling different for feeding it versus spreading it on litter?

Yes, it differs. Applying it to the environment as litter or bedding is not a feed use ingested by the animal, so it is labeled under the FDA GRAS general anticaking-agent provision 21 CFR 182.2729. When the same product is fed directly as an anticaking agent in feed, the feed-ingestion provision 21 CFR 582.2729 applies. The litter application on this page falls under the 21 CFR 182.2729 category.

Q: Does it also capture anions such as nitrate and phosphate?

No. What clinoptilolite reduces in litter is the cation ammonium (NH₄⁺). Anions such as nitrate (NO₃⁻) and phosphate (PO₄³⁻) are repelled by the negatively charged framework, so their adsorption is weak in the natural state, and metal (Ca/La/Fe·Al) or surfactant modification (SMZ) is effectively a prerequisite. Litter ammonia control is explained solely by cation-exchange logic and does not claim anion removal.

The On-Site Problem in Poultry Houses: Litter Ammonia, Footpad Dermatitis, Odor Complaints

In densely stocked poultry houses, the hardest environmental variable to manage is ammonia (NH₃) volatilizing from the litter. Most of the nitrogen in poultry manure is excreted as uric acid and, through microbial breakdown, converts to the ammonium (NH₄⁺) ⇌ ammonia (NH₃) equilibrium. The wetter the litter and the higher the pH, the more the equilibrium tilts toward gaseous NH₃, and the concentration in the house air rises quickly.

This ammonia leads to three kinds of loss. First, NH₃ above 25 ppm irritates the mucous membranes and airways of chickens, causing respiratory disease and reduced weight gain. Second, combined with wet litter it causes footpad dermatitis and hock burns, lowering carcass grade and animal-welfare scores. Third, NH₃ released outside the house is a direct cause of odor complaints and nitrogen-emission regulation. Litter ammonia management is therefore a problem in which productivity, welfare, and complaint response are all bound together.

Why Clinoptilolite Reduces Litter Ammonia — The Principle of Cation Exchange

Natural clinoptilolite has a negatively charged aluminosilicate framework, micropores of 4.0–7.0 Å, and a cation exchange capacity (CEC) of 1.6–2.0 meq/g. Because the ammonium produced in litter is a cation (NH₄⁺), it binds electrostatically and strongly to the negatively charged framework and is captured within it. The captured NH₄⁺ suppresses the very equilibrium that volatilizes into gaseous NH₃, so the ammonia concentration in house air drops.

This mechanism requires no separate modification. Because ammonium is a cation, it is adsorbed by the inherent cation exchange of natural clinoptilolite alone (the opposite of anions such as nitrate and phosphate). In model-solution tests, the ammonium adsorption capacity of natural clinoptilolite is reported at about 21 mg/g, with cases rising above 31 mg/g upon modification (Wibowo et al., Reviews in Environmental Science and Bio/Technology, 2019). In the solid, intermittently wet environment of litter, moisture absorption and NH₄⁺ capture occur simultaneously, with the added benefit of keeping the litter drier.

Field evidence in poultry has also accumulated. Nakaue et al. (1981) reported the effect of clinoptilolite on broiler performance and house environment (litter and ammonia) (Nakaue & Koelliker, Poultry Science, 1981), and Karamanlis et al. (2008) analyzed the effect of clinoptilolite on broiler performance and ammonia emission (Karamanlis et al., British Poultry Science, 2008). More recently, a study applying zeolite to both feed and litter examined growth and ammonia emission together (Poultry Science, 2024).

KMIZEOLITE's natural clinoptilolite is 97% pure and is mined and processed at the Amargosa Valley mine in Nevada, USA, with a specific surface area of 40.0 m²/g, a stable pH range of 3.0–10.0, and thermal stability to 700°C, making it stable in the litter environment. For environmental uses not ingested by animals, such as litter and bedding, the FDA GRAS general anticaking-agent provision 21 CFR 182.2729 applies, while when the same product is fed directly in feed, the feed-ingestion provision 21 CFR 582.2729 is labeled separately. The European Union has approved its use in the swine and poultry industries.

KMIZEOLITE Key Properties

Item	Value
Clinoptilolite purity	97%
Cation exchange capacity (CEC)	1.6–2.0 meq/g
Ammonium (NH₄⁺) adsorption capacity (reported in model solution)	about 21 mg/g
Specific surface area	40.0 m²/g
Pore diameter	4.0–7.0 Å
Stable pH range	3.0–10.0
Hardness	4.0–5.0 Mohs
Thermal stability	700°C
Specific gravity	1.89
Bulk density	45–54 lbs/ft³
Certifications	OMRI KMI-10365, FDA GRAS, TSCA, EN-71-3

Poultry House Application Examples: Litter Management Scenarios

Below are representative scenarios in which clinoptilolite is considered for poultry litter ammonia control in broiler and layer houses. In every application, ventilation, stocking density, and watering-line management are positioned as the primary measures, with zeolite positioned as a supplementary means that aids NH₄⁺ capture and litter drying.

Mixing into fresh litter before placement: Pre-mixing 14×40 mesh granule into fresh litter such as rice hulls or sawdust at 5–10% of litter weight, securing NH₄⁺ capture capacity from the early growing stage
Additional surface spreading during the growing period: Additional surface spreading in the later stage as the ammonia odor intensifies, focused on wet and caked areas (such as under the watering line)
Layer manure storage and pit application: Coating zeolite over the manure storage section of a layer house to lower NH₃ volatilization during storage (see Li et al. 2008)
Footpad dermatitis and odor hotspot management: Localized spreading on wet zones where footpad dermatitis frequently occurs to adsorb both moisture and ammonium
Pilot house comparison: Applying it in a single house and comparing NH₃ ppm, litter moisture, and footpad scores against a control house before deciding whether to expand to all houses

Recommended Particle Size and Product Specifications

For litter ammonia control, Medium Granule (14×40 mesh) is most suitable for litter mixing and surface spreading. The granule produces little dust and maintains an NH₄⁺ capture surface well among the litter. Powder (100 mesh) has a large adsorption surface area but is suited to localized, small-quantity use given dust generation. Refer to the table below to select the product group that fits your use.

Product group	Mesh	Particle size	Representative use
Powder	100 mesh or finer	<150μm	Pozzolan, feed, powder adsorption
Fine Granule	30×50 mesh	0.3–0.6mm	Water treatment, filtration, soil
Medium Granule	14×40 mesh	0.4–1.4mm	Filter layer, litter, bedding
Coarse Granule	8×14 mesh	1.4–2.4mm	Swimming pool, deicing, large-scale filtration
Extra Coarse	4×8 mesh	2.4–4.8mm	Packed bed, air scrubber

→ View products by mesh size · Product selection guide by use

On-Site Review Points

When applying zeolite to poultry house litter, the following items should be checked together.

Primary measures first: Ventilation rate, stocking density, and watering-line leak management are the primary variables for ammonia. Zeolite is a supplementary material that does not replace them
Litter moisture and pH management: The wetter the litter and the higher the pH, the greater the NH₃ volatilization, so monitor moisture and pH alongside zeolite application
NH₃ ppm measurement: Record NH₃ concentration (ppm) by house height, litter moisture, and footpad scores before and after application alongside a control house to quantitatively evaluate the effect (refer to the methods of Nakaue et al. 1981; Karamanlis et al. 2008)
Distinguish regulatory uses: Litter and environmental application falls under the FDA GRAS 21 CFR 182.2729 category, while direct feeding in feed is distinguished as 21 CFR 582.2729. No pharmacological effect is claimed
Avoid anion misunderstanding: The target of this application is the cation NH₄⁺. It does not claim removal of anions such as nitrate and phosphate, and anion removal presupposes metal/surfactant modification
Certification check: To use it as an organic-livestock environmental material, confirm OMRI Listed (KMI-10365) compliance

→ View TDS (Technical Data Sheet) · View MSDS (Safety Data Sheet)

Poultry Litter Ammonia FAQ

By what mechanism does clinoptilolite reduce ammonia when added to poultry house litter?

When uric acid in poultry manure breaks down in the litter, ammonium (NH₄⁺) and ammonia (NH₃) reach an equilibrium. Clinoptilolite has a negatively charged framework and a cation exchange capacity (CEC) of 1.6–2.0 meq/g, so it captures the cationic NH₄⁺ within its framework, reducing the amount that volatilizes as gaseous NH₃. Because ammonium is a cation, it is adsorbed by natural clinoptilolite without any separate modification, and an ammonium adsorption capacity of about 21 mg/g has been reported in model solutions. Nakaue et al. (1981) and Karamanlis et al. (2008) reported improvements in ammonia and house environment under poultry house and litter conditions.

Does it help with broiler footpad dermatitis and respiratory health?

High ammonia concentrations in the poultry house, together with wet litter, cause footpad dermatitis, hock burns, and mucosal and respiratory irritation. Mixing clinoptilolite into the litter adsorbs both moisture and NH₄⁺, keeping the litter drier and providing a supporting effect that lowers NH₃ volatilization (Nakaue et al. 1981). However, ventilation, stocking density, and watering-line management are the primary variables, and zeolite is a supplementary material that does not replace them.

How much should be applied per m² of litter, or per flock cycle?

In field practice, surface application to litter is typically considered in the range of 5–10% of litter weight (or about 0.5–1 kg/m²), divided into mixing into fresh litter before placement and additional surface spreading during the growing period. The 14×40 mesh granule is suited to litter surface spreading and mixing, while the 100-mesh powder is suited to localized use given dust concerns. The exact amount should be calibrated through a pilot according to litter type, stocking density, and ventilation.

Is the regulatory labeling different for feeding it versus spreading it on litter?

Yes, it differs. Applying it to the environment as litter or bedding is not a feed use ingested by the animal, so it is labeled under the FDA GRAS anticaking-agent general-use provision 21 CFR 182.2729. When the same product is fed directly as an anticaking agent in feed, the feed-ingestion provision 21 CFR 582.2729 applies. The litter application on this page falls under the 21 CFR 182.2729 category.

Does it also capture anions such as nitrate and phosphate?

No. What clinoptilolite reduces in litter is the cation ammonium (NH₄⁺). Anions such as nitrate (NO₃⁻) and phosphate (PO₄³⁻) are repelled by the negatively charged framework, so their adsorption is weak in the natural state, and metal (Ca/La/Fe·Al) or surfactant modification (SMZ) is effectively a prerequisite. Litter ammonia control is explained solely by cation-exchange logic and does not claim anion removal.

Inquiry and Sample Request

If you are considering applying zeolite to poultry litter ammonia control, please reach out through the channels below.

Notice

Applicability may vary depending on field conditions, regulations, and test results. Before actual application, a test review suited to the field conditions must always come first. Zeolite is best understood not as a cure-all for litter ammonia problems, but as a material that supports ventilation, density, and moisture management.