Feeding a Combination of Acidogenic Materials and Cation Exchangers Reduces Manure Ammonia Emissions and Improves Laying Hen Performance

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Poultry (Layers)
Use Area: Animal Housing
Technology Category: Ration Manipulation
Air Mitigated Pollutants: Ammonia

System Summary

Feeding a combination of acidogens and indigestible cation exchangers reduces manure ammonia emission rates by sequestering ammonium in the manure. Average reductions of up to 68% have been noted in production environments. Reduced levels of ammonia in the production environment improve bird and worker health, reduces bird mortality, and improves productivity.


Applicability and Mitigating Mechanism

  • Ammonia emissions are reduced through the use of alternative feed components.
  • The technology is suitable for use in any layer housing system.
  • Mitigation of manure ammonia emissions is due to a combination of reduced manure pH and cation exchangers present in the manure.


  • Overfeeding acidogenic materials can adversely affect performance and productivity.
  • Effective levels of acidogens are typically well below the threshold level at which adverse effects would be noted.
  • No adverse effects due to overfeeding cation exchangers have been noted.
  • Cation exchange capacity, buffering capacity, and selectivity for ammonium are critical to the performance of this system.
  • Acceptable ratios of acidogen to cation exchanger depend on acidogen pKa and cation exchanger buffering capacity.



Suitable acidogens and cation exchangers are available in the marketplace. Gypsum/zeolite blends are commercially available as a pre-mix. Implementation of gypsum/zeolite blends depends on feed bin availability, while admixing sodium bisulfate and either zeolite or humate can be done through a microbin system.

Per-ton feed costs are increased when the system is utilized, but increased feed costs are more than offset by reduced hen mortality, improved feed conversion and egg production, and reduced per-dozen production costs.



E. Carroll Hale III
Earth Net LLC Point of Contact:

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.