Building Flock Resilience: Trouw Nutrition’s Systemic Approach to Gut Health and Antibiotic Reduction

Dr.J.Pothanna,  Technical Manager,  Trouw Nutrition India

The poultry industry is steadily shifting toward antibiotic-free production, driven by growing concerns over antibiotic resistance, consumer demand, and regulatory changes. As a result, many farms are exploring how to maintain bird health and performance without the conventional use of antibiotic growth promoters (AGPs).

As the poultry industry moves toward antibiotic-free production to tackle antimicrobial resistance, natural alternatives—often called natural growth promoters—are becoming essential. Acidifiers help keep the gut environment unfriendly to harmful bacteria, improving digestion and feed efficiency. Probiotics, prebiotics and Synbiotics support the growth of good microbes and strengthen birds’ natural defenses. Plant-based additives and essential oils from herbs provide antimicrobial and antioxidant benefits and can make feed more appealing. By unlocking nutrients in feed, enzymes help birds absorb more and reduce undigested material that fuels bad bacteria. Newer tools, like immune-boosting compounds and bacteriophages (viruses that target specific pathogens), offer precise and sustainable ways to control disease. Together—along with good management—these options help maintain flock health and performance without relying on antibiotics.

Items	Poultry
Probiotics	🟢 🟡	🟢 -Growth Promotion and Strong scientific evidence for efficacy and commercial used.
Prebiotics	🟢 🟡	🟡-Disease prevention and strong scientific evidence for efficacy and commercial used
Organic acids	🟢 🟡
In-feed enzymes	🟢 🟡
Antimicrobial peptides	⚪️ ⚪️	⚪️- Growth Promotion, Disease prevention and some scientific evidence suggests potential efficacy
Phytochemicals	🟢⚪️
Minerals	🟢
Immune modulators	🟡 ⚪️
Vaccines	🟡
Bacteriophages	⚪️ 🔴	🔴- Disease treatment and some scientific evidence suggests potential efficacy
Source – 2017-WATT Global Media.

Acidifiers, particularly organic acids, are considered the foremost and most effective alternatives to antibiotics in poultry feed. Feed acidification using organic acids is a key strategy in poultry production for layers and broilers. By lowering the gastrointestinal pH, it inhibits harmful bacteria like Salmonella and E. coli, promoting beneficial gut microbes and improving bird health. Furthermore, organic acids in their undissociated form can penetrate bacterial cell walls, disrupting vital cellular functions through the release of hydrogen ions inside the bacterial cells. This action effectively kills or suppresses harmful bacteria. Organic acids also enhance nutrient digestibility and strengthen immunity, leading to better growth performance and egg production. This makes acidification an essential alternative to antibiotics in sustainable poultry farming.

In the concept of acidification in poultry feed, the main composition of acids includes:

v  Short-Chain Fatty Acids (SCFA) C1-C6: These include formic acid, acetic acid, propionic acid, and butyric acid. SCFAs are effective in lowering gut pH and inhibiting pathogens, mainly targeting gram-negative bacteria.

v  Medium-Chain Fatty Acids (MCFA) C7-C12: These include caprylic acid (C8), capric acid (C10), and lauric acid (C12). MCFAs have strong antimicrobial properties against various gram-positive bacteria and fungi, enhancing gut health and immunity.

v  Long-Chain Fatty Acids (LCFA) >C13: These are less commonly emphasized in acidifiers but may include fatty acids like stearic acid. LCFAs mainly serve as energy sources and contribute to feed stability when combined with other acids.

When stone grit is added to poultry feed to help hens develop strong eggshells, the calcium carbonate in the grit raises the alkalinity (pH) of the bird’s digestive system. If the gut becomes too alkaline, it can hinder the bird’s ability to absorb calcium efficiently. While simple chemical calculations may indicate that a large amount of acidifier—sometimes up to 8 kilograms per ton of feed—is necessary to counteract this alkalinity, the reality is different.

In practical poultry feeding, much smaller amounts of acidifier, typically between 1 and 3 kilograms per ton of feed, are sufficient. This is because commercial acidifiers are blends containing less pure acid along with other beneficial ingredients. Additionally, the bird’s digestive system naturally produces acids, and the beneficial gut bacteria work alongside the acidifier to maintain a balanced gut environment. Other feed components also influence gut pH, reducing the need for higher acidifier amounts. Using the right level of acidifier ensures better calcium absorption, stronger eggshells, reduced feed costs, and improved gut health

When selecting an acidifier for poultry nutrition, several important factors must be taken into account to ensure it works effectively.

v  Factors influencing the efficiency of dietary organic acid supplementation.

Ø  pKa-value

Ø  Chemical form (acid, salt, coated or not)

Ø  Molecular weight

Ø  MIC-value of the acid

Ø  Kind of micro-organism

Ø  Animal species,

Ø  Site and location in the gastro-intestinal tract

Ø  Buffering capacity of the feed

 

Buffering capacity (B-value) is a measure of how much resistance a feed must changes in pH. A feed with high buffering capacity requires more acid to reduce its pH, while a feed with low buffering capacity is easily acidified.

 Feeds rich in protein (soybean meal, fish meal) and minerals (limestone, dicalcium phosphate) tend to have high buffering capacity. High buffering capacity can make it challenging to create the acidic gut environment needed for optimal enzyme function and microbial balance. Cereal grains typically have lower buffering values.

The relationship between buffering capacity and acidifier dose is direct and important: the higher the buffering capacity of the feed, the greater the dose of acidifier needed to effectively lower the pH. In feeds with low buffering capacity, only a small amount of acidifier is required to achieve the desired acidification.

Proper balancing of acidifier dose with the feed’s buffering capacity is essential. If too little acidifier is added to a high buffering capacity diet, the pH will not decrease enough, reducing the benefits of acidification. Conversely, adding excessive acidifier can cause feed palatability issues or irritate the digestive tract.

 

Poultry GIT Site	Approximate pH Range	Common Organic Acids	Approximate pKa Value
Crop	4.5 - 5.5	Lactic acid	3.85
Proventriculus	2.5 – 3.5	Formic acid	3.75
Gizzard	2.5 – 3.5	Propionic acid	4.87
Duodenum	5 .0- 6.0	Acetic acid	4.76
Jejunum/Ileum	6.0 - 6.8	Butyric acid	4.82
Cecum	~6.5 - 7.0	Benzoic acid	4.2
Large Intestine	Near neutral	Sorbic acid	4.76
		Ammonium Formate	9.2 to 9.25

 

Single acids like formic, propionic, or citric acids are used for targeted effects, such as rapid pH reduction or energy provision in specific gut sections. For example, formic acid—with a low pKa—efficiently lowers the gut’s pH, suppressing pathogenic bacteria predominantly in the crop and proventriculus. Blends of acids, on the other hand, are preferred during periods of heightened disease risk, stress, or following the withdrawal of antibiotics. The synergistic interactions among acids in blends provide a broader antimicrobial spectrum, cover more intestinal segments, and usually require lower effective doses.

 

Based on the pH and pKa concept, the use of organic acid blends is important in poultry nutrition because gut pH varies across different segments. Since the antimicrobial effectiveness of an acid depends on it being undissociated—which is influenced by the pH relative to its pKa—a blend of acids with different pKa values ensures consistent activity throughout the entire gut. Acid blends combine short-, medium-, and sometimes long-chain fatty acids to target multiple gut regions, improving pathogen control, enhancing gut integrity, and supporting nutrient absorption. Thus, acid blends provide a broader and more reliable antimicrobial effect in the variable pH environment of the poultry gastrointestinal tract compared to single acids alone.

Conclusion

As the poultry industry embraces antibiotic-free production, a science-based approach becomes indispensable. Trouw Nutrition’s integrated model—built around Selacid Green Growth and hydroxy trace minerals—shows how gut health and performance can be optimized without antibiotics.

·    Selacid Green Growth, a blend of free and buffered short- and medium-chain fatty acids, promotes gut microbial balance, supports digestive health, and sustains performance under antibiotic-free production. Surpassing AGP equivalents in trials, it delivers comparable growth and feed efficiency without compromising bird health.

·  Hydroxy trace minerals (e.g., hydroxychloride forms of zinc, Copper, Manganese) demonstrate superior bioavailability and stability over traditional sulfates. Broilers fed these minerals show improved growth performance, enhanced gut microbiota diversity, and even better carcass traits—while reducing environmental mineral excretion

 

References –

1)      The Effect of Acidifier Supplementation on Egg Production and Quality," PMC, 2022.

2)      Makkink C. Acid binding capacity in feedstuffs. Feed International. 2001;22:24‒27