Complete Guide to Organic Acid Feed Additives: Mechanism of Action, Application Scenarios and Selection Methods

What are organic acid feed additives?

Organic acid feed additives, commonly referred to in English as organic acids feed additives, which are functional additive products mainly composed of formic acid, propionic acid, lactic acid, citric acid, butyric acid and their salts or compound products, and are applied to feed raw materials, compound feeds, animal drinking water or breeding sites.

Organic acid feed additives can act on the feed itself, the animal's digestive environment or the feed preservation process according to the product formula and use purpose. The definition of feed additives by the European Food Safety Authority also points out that feed additives can act on feed, animals, animal-derived foods or breeding environments.

In actual production, organic acid feed additives are usually used in the following directions:

• Freshness management of feed raw materials and finished feeds;
• Mold risk control of grains and high-moisture raw materials;
• Digestive and nutritional support for pigs, poultry, aquatic products and other animals;
• Acidity management of drinking water and liquid feeding systems;
• Reduce microbial risks in feed production and storage links;
• Improve feed utilization efficiency through animal nutrition programs.

It should be noted that "organic acid feed additives" refers to a chemical classification concept, and is not equivalent to "organically certified feed".

How do organic acid feed additives work?

The application effect of organic acid feed additives is usually not determined by a single mechanism, but is related to acid type, concentration, dissociation characteristics, product form, animal species, age, basic diet and breeding environment.

1. Regulate the acidity environment of feed and digestive tract

Some organic acids can reduce the pH value of specific parts of feed, drinking water or gastrointestinal tract, creating a more suitable environment for the digestion process and microbial management.

For animals with an incompletely mature digestive system, such as weaned piglets, the reasonable use of organic acid products may help improve the dietary acidity conditions and nutrient utilization. However, the results observed in different experiments are not completely consistent, and the actual effects are affected by formula, dosage, acid type and feeding conditions.

2. Support microbial risk management in feed

Some undissociated organic acids can interact with microbial cells, thus affecting the growth conditions of certain unfavorable microorganisms. Therefore, formic acid, propionic acid and their compound products are often used in feed hygiene and raw material preservation management.

A systematic review and Meta-analysis in 2025 showed that in broiler production, the supplementation of organic acids is associated with a reduction in Salmonella risk before slaughter, but the study also emphasizes that actual use still needs to be evaluated according to product dosage, safety and application methods.

3. Improve feed storage and preservation conditions

Propionic acid and propionates are often used in mildew prevention and preservation management of grains, compound feeds and high-moisture raw materials; formic acid is common in feed hygiene, liquid feeding and raw material acidification programs.

The role of organic acids in silage and feed preservation is closely related to controlling acidity, fermentation process, and stability after aerobic exposure. After feed is exposed to air, some yeasts and other microorganisms consume the original preservative organic acids, so the preservation effect also depends on sealing, moisture content, and storage management.

4. Support for digestion and nutrient utilization

Some studies have shown that organic acids and their salts may affect digestive enzyme activity, mineral utilization, intestinal microbial composition, and nutrient digestibility, but the effects are not the same for all animals, all formulas, and all doses.

Therefore, organic acid feed additives should not be used only with the idea that 'the higher the addition amount, the better the effect', but should be formulated according to animal stage, basic diet, and specific problems.

What are the common organic acid feed additives?

Formic acid and formates

Formic acid has strong acidification ability and is often used in feed ingredient hygiene management, compound feed acidification, and liquid feeding systems.

Formate products, such as calcium formate, sodium formate, and ammonium formate, usually have relatively stable properties, milder odor, and are easy to add to solid feeds. There are differences in the active ingredient content, solubility, and application purposes of different salt products.

Propionic acid and propionates

Propionic acid and products such as calcium propionate, sodium propionate, and ammonium propionate are mainly used for mildew prevention and preservation of grains, feed ingredients, and finished feeds.

The European Food Safety Authority (EFSA) considered in its 2024 assessment that under the existing authorized use conditions, propionic acid is safe for terrestrial target animals, consumers, and the environment; but concentrated propionic acid has a corrosive risk to the skin, and operators must take appropriate protection measures.

Lactic acid

Lactic acid is suitable for partial feed acidification, drinking water management, liquid feeding, and compound acid products. Its odor and palatability are usually relatively mild, and it can also be a component of compound acid solutions.

The dosage of lactic acid should be determined according to animal species, product concentration and local regulations. The safety assessment of lactic acid feed additives by the European Food Safety Authority also sets corresponding conditions according to different animal categories and usage methods.

Citric acid

Citric acid is a common solid organic acid, which is easy to transport, store and formulate. It can be used for feed acidity regulation, mineral nutrition programs and compound acid products.

In the nutritional research of poultry and pigs, citric acid is used as a feed additive and acidifying component, but the final effect is still related to dosage, diet composition and animal stage.

Butyric acid and butyrates

Butyric acid and butyrates are more applied in animal intestinal nutrition. Due to the obvious odor of free butyric acid, sodium butyrate, calcium butyrate, coated butyrates or glycerides are often used in actual products to improve processing stability and action sites.

Compound organic acids

Compound organic acids usually consist of two or more organic acids, acid salts, carriers or functional components, aiming to take into account different needs such as feed preservation, acidity regulation and digestive nutrition.

Studies show that compound organic acids have shown positive effects in some pig nutrition trials, but some studies have not observed significant improvements. This shows that compounding does not necessarily mean effectiveness, and the key still lies in acid combination, effective content, target animals and actual use conditions.

What is the difference between single organic acid and compound organic acid?

The composition of a single organic acid is clear, which is convenient for use around a certain goal. For example, propionic acid is often used for feed mildew prevention, and formic acid is often used for acidification and hygiene management.

Compound organic acids can use the dissociation characteristics, action sites and functional characteristics of different acids to cover multiple application links. For example, a compound plan can consider raw material preservation, finished feed stability and animal digestive stage at the same time.

Whether to choose single acid or compound acid should focus on considering:

• Mainly solve mold, bacteria, acidity or digestion problems;
• Whether the product is used for raw materials, finished feed, drinking water or breeding site;
• Animal species, age and production stage;
• Diet buffering capacity and raw material composition;
• Effective acid content of the product, not just the total addition amount;
• Proportion of free acid, acid salt and coated products;
• Equipment material, corrosion risk and operation safety;
• Local feed regulations and product registration requirements.

Main application scenarios of organic acid feed additives

Feed raw material management

Corn, wheat, bran, soybean meal, by-products and high-moisture raw materials may be affected by moisture, temperature and microbial conditions during storage.

For raw material preservation problems, usually need to comprehensively evaluate:

• Initial moisture of raw materials;
• Ambient temperature and humidity;
• Storage time;
• Warehouse ventilation conditions;
• Mold contamination level;
• The uniformity of organic acid coverage.

Organic acids cannot replace warehouse cleaning, ventilation, temperature and humidity management, and raw material testing; instead, they should be part of a complete feed safety management system.

Fresh-keeping of finished feed

In areas with high temperature, high humidity, long-distance transportation, or long storage periods, finished feed may face risks of caking, heating, mold, and nutrient loss.

Organic acid feed additives based on propionic acid and its salts can develop targeted solutions according to feed moisture and storage period.

Pig nutrition

Research on organic acids in pig nutrition mainly focuses on weaned piglets, fattening pigs, and sows. Some studies have observed that organic acids are related to improvements in feed intake, digestibility, intestinal environment, and growth performance, but there are differences in different test results.

Therefore, the acidification plan for pigs needs to be comprehensively designed by combining the age of piglets, raw material structure, protein level, mineral composition, and health status.

Poultry nutrition

Applications of organic acids in the poultry field include feed hygiene, water management, intestinal environment support, and Salmonella risk control.

The effect of organic acids in poultry is related to the administration route, which can be used through feed, water, or raw material treatment, but one should avoid directly applying the results of a single study to all farms.

Aquatic and other animals

Organic acids can also be used in aquatic feed, preservation of ruminant feed, and some liquid feeding systems. There are obvious differences in the digestive physiology of different animals, so product formulas, dosages, and evaluation indicators cannot directly copy the pig and poultry plans.

How to choose a suitable organic acid feed additive?

Step 1: Clarify the use goal

Main needs should be confirmed before purchasing:

• Control grain and feed mold;
• Extend the storage period of finished feed;
• Improve feed hygiene;
• Manage the water supply system;
• Support piglet or poultry digestion;
• Improve the stability of liquid feeding;
• Reduce the risks brought by raw materials of different batches.

Different goals require different acid types, concentrations, formulations and addition methods.

Step 2: Check the active ingredients

You can't just compare the product name and the addition price per ton, but should also check:

• The actual content of each organic acid;
• The ratio of free acid to acid salt;
• Moisture and carrier content;
• Coating rate or sustained-release form;
• Product pH value and buffering capacity;
• COA test items and batch stability.

Step 3: Evaluate the actual use cost

Products with lower prices don't necessarily have lower use costs. The purchaser should calculate the actual addition amount required to achieve the target effect, the effective acid cost, transportation cost, equipment adaptation cost and labor operation cost.

Step 4: Pay attention to safety and equipment compatibility

Concentrated organic acids may be corrosive and irritating. For liquid acid products, the materials of storage tanks, pumps, pipelines, valves and spraying equipment should be focused on evaluating, and necessary protective equipment should be configured for operators.

All products should be used in accordance with SDS, label instructions, local regulations, and technical personnel's recommendations.

Addeasy Group Organic Acid Application Solutions

Addeasy Group focuses on organic acid technology and applications, serving fields such as animal nutrition, fine chemicals, food additives, and plant nutrition.

In the field of animal nutrition, Addeasy Group can match solutions around the following directions according to the specific needs of feed enterprises, breeding groups, and distributors:

• Feed raw material preservation;
• Finished feed preservation;
• Feed acidification;
• Animal intestinal health;
• Digestive nutrition support;
• Liquid acidifier application;
• Drinking water and breeding site management;
• Organic acid product customization and application services.

Compared with simply providing a single organic acid product, a more reasonable way is to establish a multi-dimensional organic acid application solution according to raw materials, animals, production processes, storage environments, and use objectives.

Common Questions

Can organic acid feed additives completely replace antibiotics?

It cannot be simply understood as one-to-one replacement.

Organic acids can be an important part of non-antibiotic nutrition and feed management solutions, but animal production performance is also affected by many aspects such as biosecurity, raw material quality, formula nutrition, vaccines, environment, and breeding management.

How should formic acid and propionic acid be selected?

Formic acid usually focuses more on acidification, feed hygiene, and liquid feeding management; Propionic acid usually focuses more on mildew prevention and fresh-keeping of grains and feeds.

When customers face both feed hygiene and storage problems, they can evaluate the compound solutions of formic acid, propionic acid, and their salts.

Is a higher addition amount of organic acids better?

No.

A too low addition amount may fail to achieve the goal, while a too high addition amount may affect palatability, increase corrosion risks, or increase costs. The addition amount must be determined according to product concentration, animal species, diet structure, use purpose, and regulatory requirements.

What is the difference between organic acids and organic acid salts?

Free organic acids usually have a relatively direct acidification effect, but may have a strong odor, volatility, or corrosiveness; organic acid salts are usually more stable, facilitating solid feed processing and transportation.

Actual products often combine free acids with acid salts to balance processing performance, acidification ability, and use safety.

How to judge whether a compound organic acid product is appropriate?

It is recommended to verify through raw material testing, small-scale trials, and production data, and focus on observing:

• Feed mold and bacteria indicators;
• Storage stability;
• Animal feed intake;
• Feed-conversion ratio or feed-egg ratio;
• Diarrhea rate and health indicators;
• Drinking water or liquid feeding system status;
• Comprehensive use cost per ton of feed.