POULTRY FARMING AND WATER ACIDIFICATION
KNOWING ORGANIC ACIDS AND THEIR PROPERTIES
It is estimated that in the poultry sector, feed accounts for more than half of production costs—but why call it a cost?
Feed is actually an investment in production, and as a good entrepreneur would say, every investment must yield returns.
To make the most of feed expenses, it is necessary to increase feed efficiency, i.e., reduce the feed conversion ratio.
The performance of your flock—and consequently your profitability—depends heavily on this, which is possible only by maintaining the intestinal health of your animals. Various studies show that acidifying the diet not only provides a known antimicrobial activity but also brings significant benefits to intestinal health.
Acidification promotes food digestion, nutrient utilization, and the development of a healthy gut microbiota.
Acidifying preserves intestinal health, animal health, and your finances.
ORGANIC ACIDS: A BRIEF CHEMISTRY LESSON BEFORE STARTING
Organic acids, or carboxylic acids (R-COOH), dissociate in aqueous solution into hydrogen ions (H⁺) and the corresponding anion (R-COO⁻).
The degree of dissociation—i.e., the release of a hydrogen ion (H⁺) from the functional –COOH group—is defined by the acid’s pKa, which is the acid dissociation constant.
The lower the pKa, the greater the ability to release hydrogen ions and thus acidify the environment.
| ACID | Formula | pKa at 25°C |
| Formic acid | H-COOH | 3,75 |
| Acetic acid | CH3-COOH | 4,75 |
| Propionic acid | CH3-CH2-COOH | 4.87 |
| Butyric acid | CH3-CH2-CH2-COOH | 4,82 |
| Lactic acid | CH3-CHOH-COOH | 3.08 |
| Fumaric acid | COOH-CH=CH-COOH | 3.03/4.44 |
| Citric acid | COOH-CH2-C(OH)COOH-CH2-COOH | 3.14/5.95/6.39 |
PROPERTIES OF ORGANIC ACIDS
PROPRIETA’ ANTIMICROBICHE
The main pathogenic bacteria—E. coli, Salmonella, and Clostridium perfringens—stop multiplying at pH levels below 5 (i.e., in an acidic environment), while acidophilic bacteria like Lactobacillus spp. continue to replicate.
The mechanism is simple: the undissociated form of the acid (R-COOH) can penetrate the semi-permeable membrane of bacterial cells. Once inside, R-COOH dissociates, releasing H⁺ ions and acidifying the cytoplasm.
The cell must then expel all H⁺ ions to restore optimal pH, which requires enzymatic systems that consume energy. This energy drain weakens the bacterial cell, ultimately leading to its death.
| Formic acid | Yeasts and bacteria (E. coli and Salmonella spp.) |
| Acetic acid | Bacteria (various species) |
| Propionic acid | Molds |
| Butyric acid | Bacteria (especially E. coli and Salmonella spp.) |
| Lactic acid | Bacteria (various species) |
| Citric acid | Bacteria (various species) |
The pKa and chemical properties of acidic molecules determine their more or less pronounced antimicrobial activity, not only against different types of bacteria but also against fungi and/or yeasts. Below is a brief overview of the action spectrum of the main organic acids.
EFFECTS ON PROTEIN DIGESTION
Proteins play an essential role in the body: enzymes, hormones, and carrier molecules all rely on them. Whether for growth, egg production, immune response, or adapting to stress, proteins are fundamental.
When formulating a diet, the goal is to provide animals with high-quality proteins with an optimal balance of essential amino acids (those the animal cannot synthesize).
However, proper protein supply depends not only on the quality of the protein source but also on digestion and absorption.
Proteins are partially digested in the stomach by pepsin and further broken down in the duodenum by pancreatic enzymes. Pepsin requires an acidic environment to function effectively, which is why acidifying the diet supports protein digestion.
Acid also denatures proteins, altering their structure and further enhancing pepsin activity.
In young animals, especially during the first days after hatching, stomach acid production is limited. Early dietary acidification promotes protein digestion and supports chick development. In adults, it maintains adequate production.
Anions (R-COO⁻) released from acid dissociation also play a role by binding calcium, zinc, and other cations, enhancing the absorption of these minerals essential for animal metabolism.
MODULATION OF INTESTINAL MICROBIOTA
It is well known that organic acids significantly reduce the presence of pathogenic bacteria while increasing populations of beneficial bacteria such as Lactobacillus spp.
Organic acids have a modulatory effect on the intestinal bacterial flora (microbiota). By promoting the growth of non-pathogenic strains that line the intestinal epithelium, they prevent adhesion of pathogenic bacteria introduced through the diet. This phenomenon is called competitive exclusion.
Thus, their effect is not only direct on bacterial cells but also indirect, by preventing their adhesion to the intestinal epithelium.
EFFECTS ON THE GASTRO-INTESTINAL TRACT
Several studies report that supplementing diets with combinations of organic acids exerts a trophic/plastic effect on the intestinal epithelium, promoting the development of villi and the crypts of Lieberkühn (structures responsible for nutrient absorption, production of protective mucus, and essential molecules for digestion and intestinal defense against pathogens). This property seems to derive indirectly from the antimicrobial action of these acids. By reducing the activity of pathogenic bacteria and their toxins, normal intestinal permeability is preserved, avoiding transit alterations and nutrient malabsorption, which can cause diarrhea or diarrhea-like episodes (“undigested feed,” etc.).
The modulatory action on the microbiota that colonizes the intestine prevents the establishment of pathogens and the onset of inflammatory or sub-inflammatory states, which could lead to chronic inflammation with permanent alterations of intestinal functionality—an aspect that underlies production performance.
Studies on broilers and laying hens show that production benefits positively from the action of various combinations of organic acids. Tecnozoo has developed the best acid combinations because we understand how crucial intestinal health is for your animals.
Looking for a complete product to acidify drinking water? Try Pluriacid.
BIBLIOGRAPHY
- Dr Srijit Tripathi – “Role of Acidifiers in Poultry”
- Beulah Vermilion Pearlin, Shanmathy Muthuvel, Prabakar Govidasamy, Manojkumar Villavan, Mahmoud Alagawany, Mayada Ragab Farag, Kuldeep Dhama, Marappan Gopi – “Role of acidifiers in livestock nutrition and health: A review”
- Sohail Hassan Khana and Javid Iqbalb – “Recent advances in the role of organic acids in poultry nutrition”
- Uk Essays – “Role Of Acidifier In Poultry Biology Essay”
- Avitechnutritions – “The Role of Acidifers in Poultry Nutrition”
- Salah Esmail – “Understanding protein requirements”
- D M Matthews and L Laster – “Absorption of protein digestion products: a review”
- http://www.treccani.it/enciclopedia/acidi-organici
