PoultryEubiotics: Acidifiers

MAXCID™ Blended Feed Acidifier

Five acids. One strategy. Acidification from the crop to the cecum.

MAXCID™ is a powder acidifier that blends propionate, formate, citric acid, orthophosphoric acid and encapsulated sodium butyrate. Together they lower digesta pH, protect feed hygiene and nourish the gut lining along the full length of the digestive tract.

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98%livability at 2 kg/t, against 90% for the control
1,693 gfinal body weight at 3 kg/t, against 1,456 g for the control
pH 5.72 → 3.59ileum pH at 3 kg/t, against the control
42-day university trial, 240 Ross 308 male broilers.

Go Beyond the Stomach

Most acidifiers do their work in the upper gut and stop there. MAXCID™ is built to keep working all the way down.

Modern diets are high in protein and buffering capacity, and growth-promoting antibiotics are no longer an option in many markets. When pH in the small intestine and ceca drifts above 5.8 to 6.0, pathogens such as Salmonella and Clostridium perfringens find room to grow. Young chicks feel it first, especially in the first three weeks of life. MAXCID™ responds with a blend that works in stages.

How it works

Three Zones. One Blend.

Zone 1

Fast pH reduction in the crop and gizzard.

Zone 2

Lower pH held through the duodenum and jejunum.

Zone 3

Controlled butyrate delivery to the lower gut.

ZoneActive componentsWhat happens
Feed, crop and proventriculusPropionate, formateLower pH and suppress feed-borne bacteria and molds [2, 3]
GizzardOrthophosphoric acidRapid pH drop; also supplies available phosphorus
Duodenum and jejunumCitric acidKeeps pH low to support mineral absorption and beneficial flora [4]
Lower small intestine and cecumEncapsulated sodium butyrateReleases butyrate where enterocytes need it to support gut integrity [5, 6, 7]

Why encapsulated butyrate?

Free sodium butyrate is absorbed or neutralized in the upper gut and rarely reaches the lower intestine, where gut cells need it most. MAXCID™ uses a protective coating, so butyrate is released further down the tract [5, 6, 7].

Why five components?

Orthophosphoric acid acidifies quickly and supplies available phosphorus. Propionic, formic and citric acids are organic acids with antimicrobial activity that persists along the tract, and they are more palatable than mineral acids. Reviews of the literature favor blends over single acids, because each acid works in a different place and against different microbes [1].

Results by species

Acidifiers to Benefit Broilers

In a 42-day university trial with 240 Ross 308 male broilers, MAXCID™ delivered [8]:

Heavier birdsFinal body weight of 1,693 g at 3 kg/t, against 1,456 g for the control.
Better livabilityLivability of 98% at 2 kg/t, against 90% for the control (mortality effect significant, P ≤ 0.01).
Higher production efficiencyEuropean Production Efficiency Factor of 372 at 2 kg/t, against 335 for the control.
Lower digesta pH beyond the stomachSignificant reductions in duodenum, jejunum and ileum pH (P ≤ 0.01). Ileum pH fell from 5.72 to 3.59 at 3 kg/t.
Stronger mineral statusTibia calcium up 8.6% and magnesium up 15.7% at 3 kg/t (P ≤ 0.01).

Acidifiers to Benefit Layers

Independent studies of multi-acid blends with a profile similar to MAXCID™ have been run in laying hens at the recommended level of 3 kg/t of feed:

Heavier eggsA blend of formic, lactic, malic, citric, tartaric and orthophosphoric acids at 3 kg/t significantly increased average egg weight [10].
Gut conditions that favor performanceThe same study recorded significant changes in pH along the digestive tract [10].
Better body weight and laying rateReviews report gains in body weight and hen-day egg production with multi-acid blends in long-term trials [9].

MAXCID™ Blended Feed Acidifier

Changing regulations. Rising pressure to reduce antibiotics. Feed that has to work harder. MAXCID™ gives producers and feed mills a blend that is built for the whole gut, and tested in a controlled trial on the final formula.

The organic acids in MAXCID™ already have a defined place in European regulation: formic acid, citric acid, and propionic acid and its salts are each evaluated by EFSA as technological additives [11, 12, 13].

Products are not available in all countries. Permitted feeding levels may differ by region. Please contact your Filiz sales representative for details.

MAXCID™ Blended Acidifier Powder

A free-flowing powder acidifier for complete feed, premix and concentrate. Blends propionate, formate, citric acid, orthophosphoric acid and encapsulated sodium butyrate to acidify and protect the gut from feed to cecum.

BroilersLayers
FormPowder
Inclusion rate, broilers1 to 3 kg per tonne of feed (0.1 to 0.3%). 2 kg/t gave the lowest mortality and highest production efficiency in the trial.
Inclusion rate, layers3 kg per tonne of feed
Pack size25 kg bag
Storage and shelf lifeStore cool and dry, away from direct sunlight. 18 to 24 months from production date.

Feeding instructions: Mix uniformly into complete feed, premix or concentrate. For very high pelleting temperatures, add after conditioning or apply as a post-pellet coating. Suitable for all growth phases; in high-challenge conditions or with lower-quality raw materials, prioritize the starter phase. Avoid long contact with strongly alkaline materials in storage before mixing. Not intended for drinking water. Consult your regional nutritionist for final feeding levels.

Resources

MAXCID™ Trial at a Glance

Ross 308 male broilers, 240 birds, completely randomized design with 4 treatments × 5 replicates × 12 birds, 42 days. Faculty of Agriculture, Ferdowsi University of Mashhad, Iran [8].

MeasureControl1 kg/t2 kg/t3 kg/t
Final body weight (g)1,4561,5241,5351,693
Livability (%)90929895
Production efficiency factor335.4345.7372.1362.7
Jejunum pH5.364.864.394.27
Ileum pH5.724.704.673.59
Tibia calcium (%)31.6132.4633.7334.32
Tibia magnesium (%)0.700.730.750.81
Digesta pH along the digestive tract of broilers at 42 days for control, 1, 2 and 3 kg/t MAXCID
Figure 1. MAXCID™ lowers digesta pH from the duodenum to the ileum.

Ready to Put MAXCID™ to Work in Your Feed?

Tell us about your flock, your diets and your goals. Our technical team will help you choose the right inclusion level.

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References

  1. Abd El-Ghany, W.A. (2024). Applications of Organic Acids in Poultry Production: An Updated and Comprehensive Review. Agriculture, 14(10), 1756.
  2. Ricke, S.C., Dittoe, D.K., & Richardson, K.E. (2020). Formic Acid as an Antimicrobial for Poultry Production: A Review. Frontiers in Veterinary Science, 7:563.
  3. Paster, N. (1979). A commercial-scale study of the efficiency of propionic acid and calcium propionate as fungistats in poultry feed. Poultry Science.
  4. Hu, P., et al. (2024). Citric Acid Promotes Immune Function by Modulating the Intestinal Barrier. International Journal of Molecular Sciences, 25(2), 1239.
  5. Evaluation of encapsulated sodium butyrate on growth performance, energy digestibility, gut development, and Salmonella colonization in broilers. Poultry Science (2020).
  6. Effect of feeding protected sodium butyrate on production performance and intestinal morphology of broilers: A meta-analysis. PMC12409422.
  7. Effects of Dietary Microcapsule Sustained-Release Sodium Butyrate on the Growth Performance, Immunity, and Gut Microbiota of Yellow Broilers (2023). PMC10705809.
  8. Filiz R&D Group (2025). Effects of a commercial acidifier (MAXCID) on performance, gut health and skeletal health in broilers. 8th National Conference on Innovation in Agriculture, Animal Science and Veterinary Medicine, Iran.
  9. Application of dietary organic acids in laying hens production: a comprehensive review (2025). PMC12715441.
  10. Effect of different supplements on eggshell quality, some characteristics of gastrointestinal tract and performance of laying hens. PMC4299993.
  11. EFSA FEEDAP Panel (2014). Scientific Opinion on the safety and efficacy of formic acid when used as a technological additive for all animal species. EFSA Journal, 12(11), 3827.
  12. EFSA FEEDAP Panel (2015). Scientific Opinion on the safety and efficacy of citric acid when used as a technological additive (preservative) for all animal species. EFSA Journal, 13(2), 4009.
  13. EFSA (2011). Scientific Opinion on safety and efficacy of sodium benzoate, propionic acid and sodium propionate for pigs, poultry, bovines, sheep, goats, rabbits, horses. EFSA Journal, 9, 2357.