Mycotoxins affect intestinal health and productivity in broiler breeders

By Han Zhanqiang, Poultry Technical Manager, EWN China

Poultry meat accounts for more than one-third of global meat production. With increasing demand levels, the industry faces several challenges. Among them is the continuous supply of day-old chicks, which is affected by various issues. Mitigation strategies should be taken to ensure the supply of good quality day-old chicks to production farms.

Fast-growing broilers versus fit breeders

The poultry industry is challenged by the broiler-breeder paradox: on the one hand, fast-growing broilers are desirable for meat production. On the other hand, the parents of these broilers have the same genetic traits, but in order to be fit for reproduction, their body weight should be controlled. Thus, feed restriction programs, considering breeder nutritional requirements, are necessary to achieve breed standards for weight, uniformity, body structure, and reproductive system development, determining the success of day-old chick production.

Mycotoxins affect breeder productivity

During the rearing period, gut health problems such as coccidiosis, necrotic enteritis, and dysbiosis affect flocks. Also during the laying period, breeder flocks are also susceptible to disturbances in gut health, especially during stressful periods, leading to reduced egg production and an increase in off-spec eggs. One measure to restrain these challenges is the strict quality control of the feed. In this context, contamination with mycotoxins is an important topic. However, due to the nature of fungal contamination and limitations of sampling procedures, mycotoxins may not be detected or may be present at levels considered low and not risky.

Existing studies on mycotoxins in breeders indicate that mycotoxins can cause varying degrees of reduction in egg production and hatchability and are also associated with increased embryonic mortality. Recent studies have shown that low levels of mycotoxins interact with other stressors and may lead to reduced productivity. These losses are often mistaken for normal breeder lot variation. However, they cause economic losses far greater than normal flock-to-flock variability.

Mycotoxins impair the functionality of the gut

Low mycotoxin levels affect gut health. Individually and in combinations, mycotoxins such as DON, FUM, and T2 can impact gut functions such as digestion, absorption, permeability, immunity, and microbial balance. This is critical in feed-restricted flocks because it decreases body weight and uniformity, and in laying animals, egg production and egg quality can be reduced. Absorption of calcium and vitamin D3, which are critical for eggshell formation, depends on gut integrity and the efficiency of digestion and absorption. These factors can be adversely affected by even low mycotoxin levels: eggshells can become thin and brittle, thereby reducing hatching eggs and increasing early embryo mortality.

Prevention is the key to success in day-old chick production, therefore:

  • avoid the use of raw materials with known mycotoxin contamination.
  • use feed additives prophylactically, especially with anti-mycotoxin and antioxidant properties.

Prevention is an alternative approach to assure health and productivity in -many times unknown- mycotoxin challenges.

Figure Effect Of MycotoxinsFigure 1: Effect of mycotoxins on eggshell quality and embryo death (Caballero, 2020)

University trial shows anti-mycotoxin product improving performance

A recent study by the University of Zagreb confirmed that long-term (13 weeks) exposure to feed contaminated with mycotoxins has an impact on egg production performance – a challenge that could be counteracted by using an anti-mycotoxin product.

The negative control (NC) was offered feed without mycotoxins. In contrast, the challenged control (CC), as well as a third group, received feed contaminated with 200ppb of T2, 100ppb of DON, and 2500ppb of FMB1. To the feed of the third group, an anti-mycotoxin feed additive (Mastersorb Gold, EW Nutrition) was given on top (CC+MG).

Figure Influence On Feed IntakeFigure 2: Influence of mycotoxins on feed intake and the effect of the anti-mycotoxin product Mastersorb Gold

Figure Cumulative Number Of EggsFigure 3: The effect of mycotoxins on the cumulative number of eggs and the compensating effect of Mastersorb Gold

Figure Cumulative Egg MassFigure 4: The impact of mycotoxins on the cumulative egg mass and the countereffect of Mastersorb Gold

As expected, the contaminated feed reduced feed intake, egg production, and egg weight (Fig. 2-4). Moreover, the liver and gut were affected which was evidenced in histopathological lesion scores of the organs: the control group had the lowest score, followed by the group fed Mastersorb Gold. The challenged group without any anti-mycotoxin product scored the highest.

Breeders are susceptible to mycotoxins and need our support

Broiler breeders and day-old chick production can be affected by long-term exposure to mycotoxins, which often exceeds the tolerance range of average flocks. To reduce or even prevent the potential impact of mycotoxins, a comprehensive management strategy is crucial. This includes responsible raw material procurement, storage, and feed processing leading to high feed quality, and the consideration of breeders’ nutrient demands. The inclusion of highly effective products to manage mycotoxin risk is an additional tool to maintain breeder performance.

Natural pigmentation in poultry production: Why the right product makes all the difference

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Poultry producers worldwide use natural carotenoids in feed formulations for laying hens and pigmented broilers. With European Union regulation restricting the use of apoester to 5 ppm in animal feed, it is more relevant than ever for poultry producers that safe, natural alternatives exist. Regulatory limits for natural xanthophylls, in contrast, are set at up to 80 ppm in complete feed.  

At EW Nutrition, natural xanthophyll production is a specialized and standardized process that includes quality assurance at all stages, from planting to harvesting, extraction, and saponification. The outcome is uniform and very stable products that deliver consistent, reliable results.   

How to choose and handle pigmentation products for maximum performance? 

  • Choose a trusted pigment brand with verifiable quality controls and carotenoid handling expertise 
  • Use commercially available products in their original, unopened bags 
  • Use fresh products that are within their shelf-life period 
  • Suspend products that do not fulfill pigmentation levels after opening (e.g., a level that is one third or more below the supplier specification indicates a damaged product) 
  • Store products in closed and dark bags with little exposure to oxygen during storage 

EW Nutrition’s Colortek Yellow B pigment for poultry contains ≥ 100 g/kg of natural yellow xanthophylls extracted from the marigold flower (Tagetes erecta spp.). It achieves consistent, uniform, and high-quality coloration for egg yolk and broiler skin, as attested by independent certifications FAMI QS, ISO 14000, and ISO 9001.  

A trial was designed to compare the stability of natural Colortek Yellow B and a synthetic apoester product (Carophyll Yellow, DSM [Batch L 1954]) in a premix under challenge conditions (high level of choline chloride). As shown in Figure 1, Colortek Yellow B outperformed the apoester, offering superior stability. 

Stability in vitamin mineral premix

Figure 1. Stability in vitamin mineral premix (12.5% choline chloride, closed bag, 30°C, 75% RH) 

These results underscore that Colortek Yellow B offers the stability poultry producers require for a successful pigmentation program. As poultry producers adopt natural carotenoid alternatives, they can be assured that specialized and standardized production processes and strict quality controls guarantee these products’ reliable performance. 

Salmonella in poultry: What are the most effective natural solutions?

layer imgp1242 scaled

By Dr. Inge Heinzl, Editor, EW Nutrition

Salmonella infection in poultry is a problem for the producer because of the performance losses of his flock. At the same time, products of salmonella-contaminated animals pose a severe risk to human health. In the USA, Salmonellosis in poultry is estimated to cost $ 11.6 billion each year (Wernicki et al., 2017) and more than € 3 billion in the EU (Ehuwa, 2021). As the use of antibiotics needs to be reduced to keep them effective, Salmonella control in poultry requires new solutions. This article shows how organic acids and phy­tomolecules can help to fight this problematic disease.

Salmonellosis: what it is, how it works, and why it’s such a problem


Salmonellosis is a zoonosis, meaning that it can be easily transferred from animals to humans. The transfer can occur via different routes:

  • Direct contact with an infected animal
  • Handling or consuming contaminated animal products such as eggs or raw meat from pigs, turkeys, and chicken
  • Contact with infected vectors (insects or pets) or contaminated equipment

Frozen or raw chicken products, as well as the eggs of backyard hens, are the most frequent causes of animal-mediated Salmonella infections in humans. The following graphic shows a clear relationship between the occurrence of Salmonella in layer flocks and the event of disease in humans:

Salmonella Infection Populations Chart
(Source: Koutsoumanis et al., 2019)

The impact of Salmonella on poultry depends on the bird’s age

Within the poultry flock, there are two ways of spreading: the fecal-oral way (horizontal infection) or the infection of the progeny in the egg (vertical infection). The effects of the disease depend on the age of the birds: the younger the animals, the more severe the impact.

If the brood eggs already carry salmonellae, the hatchability dwindles. During their first month of life, infected chicks show ruffled downs and higher temperatures. Diarrhea leads to fluid losses and frequently to the chicks’ death.

Adult animals usually do not die from Salmonellosis; often, the infection remains unnoticed. During a substantial acute salmonella outbreak, the animals show weakness and diarrhea. They lose weight, resulting in decreased egg production in layers and worse growth performance in broilers. The birds need more water to compensate for the fluid losses, and their crowns and jowls appear pale.

Salmonella protects itself through an intelligent infection style

Salmonellae have developed a clever way to protect themselves. After they arrive in the gut, they attach to the epithelial cells and form small molecular “syringes” to inject divers substances into the gut cells (Type-3-injection system). These signaling substances make the gut cells bulge their membranes and enclose the bacterium. Finally, the manipulated gut cell absorbs the Salmonella, the host “allows” the bacterium to enter, and it can proliferate in the gut cells (Fischer, 2018).

When an antibiotic is attacking the bacterium, Salmonellae stop their cell division. Since many antibiotics are only effective against bacteria during cell division and growth, Salmonellae survive the attack by staying as dormant variants or persisters until the treatment stops (Fischer, 2018).

Salmonellae – a big “family”

The genus of Salmonella consists of more than 2600 serovars (Ranieri et al., 2015), of which less than 100 are relevant for humans (CDC, 2020). More than 1500 serovars belong to the Salmonella enterica subspecies that colonize the intestinal tract of warm-blooded animals. These serovars are responsible for 99 % of salmonella infections (Mendes Maciel et al., 2017). The main serovars relevant for poultry are S. Gallinarum and S. Pullorum, but also S. Enteritidis, Typhimurium, and in recent years, S. Kentucky, S. Heidelberg, S. Livingstone, and S. Mbandaka (Guillén et al., 2020).

(Source: Mkangara et al., 2020)

The zoonosis Salmonellosis must be controlled

Several Salmonella serovars are critical for animals and humans. Since more than 91,000 salmonellosis cases are reported for Europe and more than 1.35 million for the USA every year (EFSA, 2022; FDA, 2020), their spread must be prevented by all means. Governments have enacted some laws to curtail this disease. The EU, for example, implemented extended control programs for zoonotic diseases, with Salmonella set as a priority. These programs include the provision of scientific advice, targets for reducing Salmonella in poultry flocks, and restrictions on the trade of products from infected flocks.

For farmers and vets, this means the obligation to notify the occurrence of the disease to the authorities. Depending on the country, it also entails compulsory vaccination and the documentation of hygienic measures. In the EU, due to the risk of developing resistances, the EFSA recommends limiting the use of antimicrobials to individual cases, e.g., to prevent inordinate suffering of animals.

Prevention of Salmonella infection is the key

The best strategy for salmonella control is prevention based on three key points (Visscher, 2014):

  • Preventing the introduction of Salmonella into the farm/flock through effective hygiene measures
  • Preventing the spread of the pathogens within a flock/farm
  • Prophylactic measures to recover immune resistance of the animals against Salmonella infection

For this purpose, the following steps are requested/recommended:

1.    Keeping the litter dry

The use of well-absorptive material such as wood shavings, straw pellets, or straw granulates and regular removal of the used litter is recommended. The animals must be controlled for diarrhea to avoid wet droppings. The water supply must be adequate; an excessive water supply wets the litter.

2.    Providing a clean environment

To keep the poultry house clean, broken eggs and dead animals (potential sources of infection) must be removed. In general, the houses should be cleaned and disinfected before every restocking.

Clean feed and water are essential; therefore, feed should not be stored outside but be kept dry and protected from pests and rodents. The feeding of the animals should take place inside to avoid contamination by wild birds. Concerning the water for drinking, the flow rate must be high enough to provide the birds with sufficient water but not too high that the floor gets wet. The troughs must be clean from droppings.

3.    Limiting contacts

To limit the spread of Salmonella, only a restricted number of persons can have access to the flocks. They must wear clothes, and instruments should be exclusively used for the respective poultry house.

Knowing the optimal growth conditions for Salmonella facilitates control

Salmonellae are a genus in the family of Enterobacteriaceae. They are gram-negative, rod-shaped (size: approx. 2 µm), glucose-fermenting facultative anaerobes that are motile due to peritrichous flagella. Since Salmonellae do not form spores, they can be easily destroyed by heating them to 60°C for 15-20 min (Forsythe, 2001), especially in food/feed with higher water content.

Salmonella facilitates control

For the storage of food, Bell and Kyriakis (2002) found that most serovars of Salmonella will not grow at temperatures lower than 7°C and a pH lower than 4.5. Wessels et al. (2021) showed optimal growth conditions for Salmonella: temperatures between 5 and 46°C (optimum 38°C), a water activity of 0.94-0.99, and a pH of 3.8-9.5.

A high fat content in the feed or food increases the likelihood of infection with Salmonella because the fat protects the bacteria during the passage through the stomach. Doses of 10 to 100 Salmonella cells can already pose a severe risk (University of Georgia, 2015).

Natural alternatives to antibiotics: effective Salmonella control?

To reduce the incidence of Salmonella while simultaneously lowering the use of antibiotics in animal production, there are different possibilities. On the one hand, veterinary medicine offers vaccines. On the other hand, the feed industry provides additives that strengthen the immune system, improve gut health, or support the animals in another manner. Other than pro- and prebiotics, the main active ingredient categories for such additives are organic acids and phy­tomolecules.

Organic acids worsen the conditions for Salmonella

Already in ancient Egypt, the method of fermentation and the generated acids have been used for the conservation of food (Ohmomo et al., 2002). Nowadays, it is a standard tool to protect feed  (silage) and food from spoilage. Also for animals, organic acids added to the feed or the water have proven helpful against pathogens. These modes of action can be combined against Salmonella: reducing the pathogen load in the feed to limit the intake of bacteria and fighting against these pathogens in the animal.

Organic acids reduce Salmonella in feed materials

In general, the antimicrobial activity of organic acids in feed is based on lowering the pH (Pearlin et al., 2019). pH-sensitive bacteria such as Salmonella minimize their proliferation at a pH <5. Additionally, the organic acids attack bacteria directly. The acid’s undissociated and more lipophilic form penetrates the bacterial cell membrane. At the neutral pH within the cell, the acid dissociates, releases protons, and lowers the pH, leading to the impediment of metabolic processes in the cell. The cell spends a lot of energy trying to get the pH back to neutral (Mroz et al., 2006). Additionally, the anions become toxic for the cell metabolites and disrupt the membrane (Russel, 1992).

What do organic acids do in the bird?

According to Hernández and co-workers (2006) and Thompson and Hinton (1997), the addition of organic acids to the feed does not change the pH in the various digestive tract segments. Still, literature shows a clear reduction of Salmonella in the gut or litter when using propionic or/and formic acid (McHan and Emmett, 1992; Hinton and Linton, 1988; Humphrey & Lanning, 1988). A likely mode of action is described by Van Immerseel et al. (2004). He asserts that SCFAs such as propionic and formic acid as well as MCFAs can inhibit Salmonella’s penetration of the intestinal epithelium and, therefore, can control these invasive phenotypes of Salmonella (S. Typhimurium and S. Enteritidis).

Different acids show different efficacy

Depending on the acid, the efficacy against Salmonella varies (see figure 3). Formic acid shows the highest effect, followed by fumaric acid. Then, lactic, butyric, and citric acid follow, showing lower efficacy.

Efficacy of different organic acids against Salmonella
Figure 3: Efficacy of different organic acids against Salmonella in feed

Trials prove the efficacy of organic acids

An in-vitro trial was conducted at a commercial research facility in the US to test the efficacy of Acidomix AFL, a liquid mixture of propionic and formic acid, against Salmonella. The bacterial strain used in these studies was nalidixic acid-resistant Salmonella typhimurium. The bacteria were maintained in broth cultures of tryptic soy broth.

They were added to 5 g of dry feed in a 50 ml tube to a final concentration of 40,000 CFU/g. Next, Acidomix AFL was added to the desired inclusion rate, and the samples were incubated at room temperature. After 18 to 72 hours of incubation, viable bacteria were counted using the plate count method.

Results: As shown in figure 4, the trial found that at an inclusion rate of 2.0 %, Salmonella inhibition was nearly 100 %. Already at a 0.4 % inclusion rate, Salmonella could be reduced by 45-60 %, showing a clear dose dependency.

Efficacy of Acidomix AFL (liquid) on Salmonella Typhimurium in dry feed
Figure 4: Efficacy of Acidomix AFL (liquid) on Salmonella Typhimurium in dry feed

Phytomolecules combat Salmonella through complex modes of action

Plants produce phytogenic substances to protect themselves from molds, yeasts, and bacteria, among others. After several purification steps, these phy­tomolecules can be used to fight Salmonella in poultry. They work through different modes of action, from attacking the cell wall (terpenoids and phenols) to influencing the genetic material of the pathogenic cells or changing the whole morphology of the cell.

Due to the different modes of action, it was long thought that there would be no resistance development. Still, Khan et al. (2009) found some microorganisms such as multidrug-resistant E. coli, Klebsiella pneumoniae, S. aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Salmonella typhimurium can show a certain – perhaps natural – resistance to some components of herbal medicines.

Gram-negative bacteria such as Salmonella are usually less attackable by phytomolecules because the cell wall only allows small hydrophilic solutes to pass; however, phy­tomolecules are hydrophobic. However, mixing the phytomolecules with an emulsifier facilitates the invasion into the cell. Their efficacy depends on their chemical composition. It is also decisive if single substances or blends (possible positive or negative synergies) are used.

The best-clarified mode of action is the one of thymol and carvacrol, the major components of the oils of thyme and oregano. They can get into the bacterial membrane and disrupt its integrity. The permeability of the cell membrane for ions and other small molecules such as ATP increases, decreasing the electrochemical gradient above the cell membrane and the loss of energy equivalents.

Trials show the efficacy of phy­tomolecules against Salmonella

Two different phytogenic compositions were tested for their efficacy against Salmonella.

Trial 1: Blend of phy­tomolecules and organic acids shows best results in an in-vitro assay

To evaluate its potential as a tool for antibiotic reduction, a trial was conducted to test the antimicrobial properties of Activo Liquid, a mixture of selected phy­tomolecules and an organic acid designed for application in water. The laboratory test was carried out at the Veterinary Diagnosis Department of Kasetsart University in Thailand. Standardized suspensions [1×104 CFU/ml] of three poultry-relevant Salmonella strains were incubated in LB medium, either without or with Activo Liquid. The tests were run at concentrations of 0.05%; 0.1%; 0.2% and 0.4%. After incubation at 37°C for 6-7 hours, serial dilutions of the cell suspensions were transferred onto LB agar plates and incubated for 18-22h at 37°C. Subsequently, colonies (CFU/ml) were determined.

Results: Activo Liquid was found to be growth-inhibiting to all Salmonella strains from a concentration of 0.1% onwards. At 0.2%, Activo Liquid already exhibited bactericidal efficacy against all tested Salmonella isolates, which was confirmed at a concentration of 0.4%.

Inhibiting effect of Activo Liquid against three different Salmonella serovars
Table 1: Inhibiting effect of Activo Liquid against three different Salmonella serovars

Trial 2: Blend of nature-identical phy­tomolecules inhibits Salmonella

On Mueller Hinton agar plates where Salmonella enterica were spread uniformly, small disks containing 0 (control, only methanol), 1, 5, and 10 µl of Ventar D were placed and incubated at 37 °C for 16 hours. The presence of clearing zones indicates antimicrobial activity.

Additionally, a motility test was performed in tubes with a motility test medium containing 0 (control) and 750 µL Ventar D. For this purpose, one colony of Salmonella enterica grown on the agar was stuck in the middle of the medium and incubated at 37 °C for 12-16 hours. Growth can be visualized through the formation of red color.

Result: Ventar D inhibited S. enterica in a dose-dependent manner. Clearing zones were visible within the lowest tested concentration. At its inhibitory concentration, Ventar D suppressed S. enterica motility (figures 5 and 6).

S. enterica motility test
Figure 5: S. enterica motility test

Disk diffusion assay employing S. enterica
Figure 6: Disk diffusion assay employing S. enterica

Let’s fight Salmonella through effective and sustainable natural tools

The zoonosis Salmonella generates high costs in the poultry industry. As Salmonellosis can be transferred to humans, it must be kept under control by all means. Antibiotics are one tool to fight Salmonella, but they have their “side effects”: they are no longer well respected by the consumer, and, even more critically, they create resistance. To help keep antibiotics effective, poultry producers seek to use effective but not resistance-creating natural solutions against Salmonella.

As shown with the reviewed trials, organic acids and phytomolecules are highly active against diverse Salmonella serovars. Accordingly, feed additives based on these active ingredients offer effective tools for controlling Salmonella in poultry while also contributing to the overarching aim of reducing antibiotic use in poultry production.


Bell, Chris, and Alec Kyriakides. Salmonella: A Practical Approach to the Organism and Its Control in Foods. Oxford: Blackwell Science, 2002.

Castro-Vargas, Rafael Enrique, María Paula Herrera-Sánchez, Roy Rodríguez-Hernández, and Iang Schroniltgen Rondón-Barragán. “Antibiotic Resistance in Salmonella Spp. Isolated from Poultry: A Global Overview.” October-2020 13, no. 10 (October 3, 2020): 2070–84.

CDC. “Serotypes and the Importance of Serotyping Salmonella.” Centers for Disease Control and Prevention, February 21, 2020.

EFSA. “Salmonella.” European Food Safety Authority. Accessed February 1, 2022.

Ehuwa, Olugbenga, Amit K. Jaiswal, and Swarna Jaiswal. “Salmonella, Food Safety and Food Handling Practices.” Foods 10, no. 5 (2021): 907.

FDA. “Get the Facts about Salmonella.” U.S. Food and Drug Administration, July 28, 2020.

Fischer, Andreas. “Clever Infiziert – Die Tricks Der Bakterien.” HZI – Helmholtz Zentrum für Infektionsforschung, August 19, 2021.

Forsythe, Steve J. The Microbiology of Safe Food. Hoboken, NJ: Wiley-Blackwell, 2020.

Gheisari, A.A., M. Heidari, R.K. Kermanshahi, M. Togani, and S. Saraeian. “Effect of Dietary Supplementation of Protected Organic …” WPSA, 2007.

Guillén, Silvia, María Marcén, Ignacio Álvarez, Pilar Mañas, and Guillermo Cebrián. “Stress Resistance of Emerging Poultry-Associated Salmonella Serovars.” International Journal of Food Microbiology 335 (2020): 108884.

Hernández, F., V. García, J. Madrid, J. Orengo, P. Catalá, and M.D. Megías. “Effect of Formic Acid on Performance, Digestibility, Intestinal Histomorphology and Plasma Metabolite Levels of Broiler Chickens.” British Poultry Science 47, no. 1 (2006): 50–56.

Hinton, M. “Antibacterial Activity of Short-Chain Fatty Acids.” The Veterinary Record 126 (n.d.): 416–21.

Hinton, M., and A. Linton. “Control of Salmonella Infections in Broiler Chickens by the Acid Treatment of Their Feed.” Veterinary Record 123, no. 16 (1988): 416–21.

Humphrey, T. J., and D. G. Lanning. “The Vertical Transmission of Salmonellas and Formic Acid Treatment of Chicken Feed: A Possible Strategy for Control.” Epidemiology and Infection 100, no. 1 (1988): 43–49.

Khan, Rosina, Barira Islam, Mohd Akram, Shazi Shakil, Anis Ahmad Ahmad, S. Manazir Ali, Mashiatullah Siddiqui, and Asad Khan. “Antimicrobial Activity of Five Herbal Extracts against Multi Drug Resistant (MDR) Strains of Bacteria and Fungus of Clinical Origin.” Molecules 14, no. 2 (2009): 586–97.

Koutsoumanis, Kostas, Ana Allende, Avelino Alvarez‐Ordóñez, Declan Bolton, Sara Bover‐Cid, Marianne Chemaly, Alessandra De Cesare, et al. “Salmonella Control in Poultry Flocks and Its Public Health Impact.” EFSA Journal 17, no. 2 (2019).

Maciel, Bianca Mendes, Rachel Passos Rezende, and Nammalwar Sriranganathan. “Salmonella Enterica: Latency.” Current Topics in Salmonella and Salmonellosis, 2017.

McHan, Frank, and Emmett B. Shotts. “Effect of Feeding Selected Short-Chain Fatty Acids on the in Vivo Attachment of Salmonella Typhimurium in Chick Ceca.” Avian Diseases 36, no. 1 (1992): 139.

Mkangara, M. and M., R. Mwakapuja, J. Chilongola, P. Ndakidemi, E. Mbega, and M. Chacha. “Mechanisms for Salmonella Infection and Potential Management Options in Chicken.” The Journal of Animal & Plant Sciences 30, no. 2 (April 2, 2020): 259–79.

Mroz, Z., S.-J. Koopmans, A. Bannink, K. Partanen, W. Krasucki, M. Øverland, and S. Radcliffe. “Chapter 4 Carboxylic Acids as Bioregulators and Gut Growth Promoters in Nonruminants.” Biology of Growing Animals, 2006, 81–133.

OHMOMO, Sadahiro, Osamu TANAKA, Hiroko K. KITAMOTO, and Yimin CAI. “Silage and Microbial Performance, Old Story but New Problems.” Japan Agricultural Research Quarterly: JARQ 36, no. 2 (2002): 59–71.

Ranieri, Matthew L., Chunlei Shi, Andrea I. Moreno Switt, Henk C. den Bakker, and Martin Wiedmann. “Comparison of Typing Methods with a New Procedure Based on Sequence Characterization for Salmonella Serovar Prediction.” Journal of Clinical Microbiology 51, no. 6 (2013): 1786–97.

Russell, J.B. “Another Explanation for the Toxicity of Fermentation Acids at Low Ph: Anion Accumulation versus Uncoupling.” Journal of Applied Bacteriology 73, no. 5 (1992): 363–70.

Thompson, J. L., and M. Hinton. “Antibacterial Activity of Formic and Propionic Acids in the Diet of Hens on Salmonellas in the Crop.” British Poultry Science 38, no. 1 (1997): 59–65.

USDA – United States Department of Agriculture – Research, Education & Economics Information System. University of Georgia, 2015.

“USDA Launches New Effort to Reduce Salmonella Illnesses Linked to Poultry.” USDA, October 19, 2021.

Van Immerseel, F., J. B. Russell, M. D. Flythe, I. Gantois, L. Timbermont, F. Pasmans, F. Haesebrouck, and R. Ducatelle. “The Use of Organic Acids to Combatsalmonellain Poultry: A Mechanistic Explanation of the Efficacy.” Avian Pathology 35, no. 3 (2006): 182–88.

Van Immerseel, Filip, Jeroen De Buck, Isabel De Smet, Frank Pasmans, Freddy Haesebrouck, and Richard Ducatelle. “Interactions of Butyric Acid– and Acetic Acid–Treated Salmonella with Chicken Primary Cecal Epithelial Cells in Vitro.” Avian Diseases 48, no. 2 (2004): 384–91.

Visscher, C. “Über Das Futter Helfen – Den Salmonellen Das Leben Schwer Machen.” Bauernblatt Schleswig-Holstein + Hamburg 68/164, no. 51 (December 20, 2014): 66–68.

Wernicki, Andrzej, Anna Nowaczek, and Renata Urban-Chmiel. “Bacteriophage Therapy to Combat Bacterial Infections in Poultry.” Virology Journal 14, no. 1 (September 16, 2017).

Wessels, Kirsten, Diane Rip, and Pieter Gouws. “Salmonella in Chicken Meat: Consumption, Outbreaks, Characteristics, Current Control Methods and the Potential of Bacteriophage Use.” Foods 10, no. 8 (2021): 1742.

5 ways the liver keeps the avian body running

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By Dr. Inge Heinzl, EW Nutrition

The liver is one of the most active organs within the avian body. Without the liver, the brain would not work, for example. Whenever glucose is not readily available for energy, the brain relies on ketone bodies provided by the liver. The liver also transforms and detoxifies substances foreign to the body (e.g., coccidiostats) and plays a role in immune defense. But how does the liver metabolism function exactly? Find out why it is so important to protect this crucial organ.

5 ways the liver keeps the avian body running

5 ways the liver keep the avian body running

The liver fulfills various essential functions. The avian liver:

  • Provides the ‘fuel’ for all organs
  • Supplies the body with essential substances
  • Acts as a storage organ
  • Is part of the immune defense
  • Supports the detoxification of the body

1.     The liver provides the ‘fuel’ for organs

The brain, the muscle, the different organs of the body – all need energy to function. This fuel is provided by the liver. And it caters to different preferences, too: the different organs need different substances as fuel. The brain usually uses glucose and, in the case of necessity (hunger), ketone bodies. Skeletal muscles work with glucose and, if glucose is lacking, fatty acids for energy generation. Heart and liver gain energy through the ß-oxidation of fatty acids.

The liver adapts to different situations

After they arrive in the gut, most of the nutrients are transported from the small intestine via the portal vein to the liver. There, they are further processed. Regardless of the nutritional supply, the liver must continuously provide energy for the other organs. In the following, different situations of energy availability are described.

1.      Just after feed intake

After feed intake, there is enough energy to be metabolized. Glucose then is further processed as follows:

  • Part of the glucose directly serves as ‘fuel’ for different organs
  • Another part is transformed into glycogen by the liver and stored in situ (glycogen is a storage substance that can be easy retransformed into glucose)
  • Some glucose is metabolized into acetyl coenzyme A (acetyl-CoA), which can be used to synthesize fatty acids. Fatty acids’ esterification with glycerol, in turn, results in the production of triglycerides. The liver can also synthesize triglycerides from lactate. The lactate comes from the muscles or the mucosa cells. In mammals, lipid tissue is  the primary place for triglyceride synthesis. In contrast, in poultry, the “de novo lipogenesis” site is the liver (Stevens, 2004). These triglycerides are subsequently:
    • stored within the hepatocytes
    • transported as “very-low-density lipoproteins” (VLDLs), a water-soluble transport form, in the blood to other organs or the adipose tissue, or
    • used for energy generation or as an energy store in the other organs or adipose tissue.

Insulin is involved in these actions, promoting the synthesis of fatty acids out of carbohydrates as well as the synthesis of VLDLs.


The role of the liver in the fed state

Figure 1: The role of the liver in the fed state [Zaefarian et al., 2019, Hermier, 1997]

2.      Between meals – the blood glucose level decreases

Some time has passed since the last feed intake; glucose has been transported from the blood to the cells. However, the organs continue to need energy, which has to be released continuously from the organs in which it is stored:

  • In the liver and the kidneys, the stored glycogen must be broken down into glucose, triggered by the hormone glucagon
  • In the skeletal muscles, glycogen is metabolized aerobically to CO2 and H2O or anaerobically to lactate
  • The liver uses lactate for gluconeogenesis, stimulated by free fatty acids released from the degradation of depot fat

The role of the liver in the state of decreasing energy

Figure 2: The role of the liver in the state of decreasing energy [Braun and Sweazea, 2008; Sturkie, 2012; Stevens, 2004]

3.      Starvation – reserves are depleted

If the glycogen reserve in the liver is depleted after some hours since the last feed intake, fatty acids are degraded to ketone bodies in the skeletal muscles. In parallel, protein degradation frees up glucogenic amino acids that the liver can use for gluconeogenesis. The lactate from the anaerobe degradation of glucose in the skeletal muscles and glycerol can also be used for gluconeogenesis. In mammals, pyruvate is the best substrate for gluconeogenesis; in poultry, it is lactate.

Gluconeogenesis also takes place in the kidneys. During starvation, 30% of the gluconeogenesis is done by the kidneys and 70% by the liver. Birds are generally able to sustain higher rates of gluconeogenesis than mammals (Stevens, 2004).

To meet the brain’s energy requirements, the liver transforms fatty acids into ketone bodies; they are the only source of energy the brain accepts besides glucose. Although the liver is the main site of ketone production, its ability to use them is limited.

During starvation, glycogen storage in the heart muscle increases. Glycogen levels in the heart muscle are usually relatively low (1.60-2.00 mg / g); in the case of starvation, these levels may triple within 48-92 hours (Hazelwood, 1976) – probably an effect of increased gluconeogenesis.

The role of the liver in the state of starvation

Figure 3: The role of the liver in the state of starvation [Frias-Soler et al., 2021; Braun and Sweazea, 2008; Sturkie, 2012]

The efficiency of glucose utilization changes

Depending on the catabolic pathway, the efficiency of glucose utilization varies considerably. Moreover, the age or development of the body is a decisive factor. Table 1 shows the variation in  glucose utilization depending on age. In all cases, the efficiency of glucose utilization increases with age. However, the efficiency of lipogenesis increases most, which is one reason  why older animals tend to get fat.

Table 1: Utilization of glucose for glycolysis (energy generation), glycogenesis (storage), and lipogenesis (storage) in gallus gallus, based on Scanes, 2015

Age (days) Glucose utilization1 (as a percentage of plateau level)
Glycolysis2 Glycogenesis Lipogenesis
Late embryo and day 0 13.3 ± 0 ˂ 0.5 < 0.5
2 51.1 ± 6.4 10.0 ± 4.1 4.0 ± 1,0
4 85.4 ± 5.5 8.3 ± 0 36.8 ± 9.8
8 104.4 ± 4.6 7.6 ± 1.1 94.7 ± 14.7
12 84.5 ±10.5 34.8 ± 9.4 66.8 ± 10.4
16 120.8 ± 12.5 105.1 ± 24.5 144.2 ± 29.0

1Determined by utilization of [U _14 C] Glucose      2Plateau conversion to CO2: 1261 dpm/mg calculated from Goodridge (1968a)
Bold data are at plateau

2.     The liver supplies the body with essential substances

The liver is involved in many processes in the organism. It takes part in protein synthesis, provides the building blocks for metabolic processes, and, hence, is essential for the body’s smooth functioning.

The liver produces various proteins

The liver is an important organ for  protein synthesis. Most of the plasma proteins (90%) such as albumins, globulins (γ-globulins excluded) are produced by the liver. The liver also synthesizes transport proteins (e. g. for copper, retinol, iron), coagulation factors, and non-essential amino acids. For this purpose, amino acids, arriving from the gut via the portal vein, are transformed through deamination and transamination (Dhawale, 2007).

Cholesterol is an essential building block for further processing

The liver produces cholesterol, a building block for the production of bile, steroid hormones, and vitamin D. Cholesterol is also an essential ingredient of the cell membrane.

As a bile producer,  the liver plays a significant role in digestion. In the gut, the bile emulsifies the dietary fats into small droplets, which then can be absorbed via the gut cells (enterocytes) into the body. The bile is also a transport medium for waste products, through delivery into the gut lumen  (detoxification function).

The liver plays a prominent role in egg production

In poultry, the composition of the egg depends on the liver. Egg yolks consist of water (70%), proteins (10%), and lipids (20%). The yolk lipids are lipoproteins rich in triglycerides, built up in the liver and transported as egg yolk-specific VLDLs (VLDLy) to the ovary. Also, cholesterol is transported via lipoproteins to the egg yolk.

3.     The liver acts as a storage organ

The liver is a storage organ for blood and glycogen (energy metabolism). Also, minerals (sodium) and trace elements such as copper, manganese,  fluor, iodine, selenium, chlorine, and iron are retained. The liver has the highest participation in the Mn metabolism, and iron is accumulated as ferritin.

Vitamin A is stored in the highest concentrations after the transformation of carotin. The liver also accumulates vitamins D, K, B1, B12, C, riboflavin, pantothenic acid, nicotinic acid, folic acid, and biotin (Dhawale, 2007).

4.     The liver is part of the immune defense

The liver filters the blood and, in this way, removes microorganisms (e.g., those originating from the gastrointestinal tract), toxins, and aged erythrocytes. For its immunological tasks, the liver has different types of immune-competent cells at its disposal. The so-called Kupffer cells are liver-specific macrophages descending from monocytes and belonging to the specific immune defense. They represent 80-90% of all tissue macrophages (Hinghofer-Szalkay, 2021).

In a healthy liver, the Kupffer cells can eliminate about 95% of the bacteria arriving through the blood. The main task of these cells is to ingest the enemies, process them, and surface parts of them as antigenic material. Besides the phagocytosis of bacteria, Kupffer cells can also incorporate toxins, immune complexes, parts of cells, and viruses. They excrete cytokines, provoking the production of acute-phase proteins (e.g., fibrinogen), fending off tumor cells and regulating the function of other liver cells. With the help of the Kupffer cells, the liver transforms or completely degrades toxins ingested with the feed (e.g., mycotoxins) (Zaefarian, 2019).

5.     The liver supports the detoxification of the body

One example is nitrogen, a product of the protein metabolism that must be excreted in an energy-intensive process via the liver and the kidneys. Ammonia and keto acids are formed by deamination. As ammonia has a toxic effect in birds, it is transformed to uric acid, transported to the kidneys, and excreted from there.

The liver is also responsible for at least the partial conjugation of already used hormones (transformation into water-soluble substances), which are then excreted via the bile. Furthermore, it assists in the degradation of red blood cells. The Kupffer cells in the liver phagocytize (“eat”) overaged red blood cells. Reusable substances such as iron are kept, the useless residual is degraded and excreted (Hinghofer-Szalkay, 2021).

Poultry producers have to do their best to protect the liver

The liver fulfills critical tasks for the body, such as detoxification, immune defense participation, and energy management.

Animal liver protectionFor meat-producing animals, growth is a critical factor. The growth rate is determined by cell growth, which depends on the speed of cell division and the synthesis of protein in the liver and muscle cells. It furthermore depends on the production and secretion of growth-regulating hormones and related metabolism processes that also take place in the liver.

Thus, to keep animals in good health and maintain high growth performance,the protection of the liver should be a top priority for the producer.



Dhawale, Avinash. “The Liver: a Big Organ with a Big Role.” World Poultry 23, no. 10 (November 23, 2007): 34–36.

Grashorn, M. “Eiqualität.” Essay. In Legehuhnzucht Und Eiererzeugung: Empfehlungen für Die Praxis Spec. issue 322, Spec. issue 322:19–33. Braunschweig, Germany: Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Raüme, Wald und Fischerei, 2009.

Hinghofer-Szalkay, H. “Eigenschaften Und Aufgaben Hepatischer Nichtparenchymzellen.” Physiologie nicht-parenchymale Leberzellen Funktion. Accessed December 21, 2021.

Scanes, C. G. “Carbohydrate Metabolism.” Essay. In Sturkie’s Avian Physiology; 6th Ed., 443. London: Academic Press/Elsevier, 2015.

Scanes, C. G., and Paul D. Sturkie. “Adipose Tissue and Lipid Metabolism.” Essay. In Sturkie’s Avian Physiology ; 6th Ed., 443. London: Academic Press/Elsevier, 2015.

Stevens, Lewis. “Carbohydrate and Intermediary Metabolism.” Essay. In Avian Biochemistry and Molecular Biology, 3rd ed., 29–36. Cambridge <<>>: Cambridge Univ. Press, 2004.

Zaefarian, Faegheh, Mohammad Abdollahi, Aaron Cowieson, and Velmurugu Ravindran. “Avian Liver: The Forgotten Organ.” Animals 9, no. 2 (2019): 63.

Broiler production with reduced antibiotics. The essentials

poultry broiler shutterstock 1228945888 small

By Dr. Inge Heinzl, Marisabel Caballero, Dr. Twan van Gerwe, and Dr. Ajay Bhoyar – EW Nutrition

Concerns about antibiotic resistance in humans and production animals have prompted a push across the board to reduce antibiotic use, including in livestock rearing. To meet these demands, the industry must keep the pathogenic pressure in production units as low as possible, enabling production with no antibiotics or minimum use of antibiotics.

Broiler production

The 3 essential steps for reducing antibiotics in broiler production

In the following, we discuss experience-based insights and practical advice concerning best practices for broiler meat production with reduced antibiotic use, focusing on the following points:

  • Farm biosecurity
  • Management of the broiler house, including cleaning & disinfection, and environment & litter management
  • Management of the flock, including DOC quality, disease prevention, and nutrition

1. General farm biosecurity

Biosecurity is the foundation for all disease prevention programs (Dewulf et al., 2018). Thus, it is essential in antibiotic reduction scenarios. It includes all measures taken to reduce the risk of introducing and spreading diseases, preventing diseases, and protecting against infectious agents. Its fundament is the knowledge of disease transmission processes.

The application of consistently high biosecurity standards substantially reduces antimicrobial resistance by preventing the introduction of resistance genes into the farm and lowering the need to use antimicrobials (Davies & DWales, 2019).

First of all: everyone must act in concert!

Biosecurity is one of the preconditions for the success of an ABR program, and it is crucial to bring all workers/staff on track through regular training on the best practices and their subsequent rigorous implementation.  The biosecurity plan can only be effective if everyone on the operation follows it – all the time. Farm managers, poultry workers, and other persons entering the facility should adhere to the farm biosecurity measures, 24/24h – 7/7d.

Separation helps to prevent the spread of pathogens

One essential component for biosecurity is implementing a “line of separation” for the farm and each house. It is vital to have a good separation between high and low-risk animals and between areas on the farm that are dirty (general traffic) and clean (internal movements). In this way, it is not only possible to avoid the entrance but also the spread of disease, as potential sources of infection (e.g., wild birds) cannot reach the farm population.

The farm must be well isolated, not allowing the entry or passage of persons who do not work there and animals, including pets.

Inside the farm, the walls of the poultry house form the first line of separation, and the “Two-zone Danish Entry Protocol” constitutes a second line. This system utilizes a bench to divide the anteroom of a poultry house into two sides (outdoor / ‘dirty area’ and indoor / ‘clean area’). At a minimum, footwear should be changed, and hands washed or disinfected when passing over the bench; it is even better when workers have house-specific clothing and hairnets when entering the poultry area.

Safety procedures on the poultry farm

Figure 1: Safety procedures on the poultry farm – the Danish entry method

The room is divided into “dirty” and “clean” zones.

  1. After the entrance from outside, workers/visitors step into a disinfectant boot tray.
  2. They take off their street shoes and leave them on the dirty side of the entrance zone.
  3. Then, they turn from the dirty to the clean side by swinging their legs without touching the floor.
  4. They wash their hands and disinfect them by using the hand.
  5. They must put on an overall, cap, mask, and boots of the poultry house.
  6. Completely clothed, they can enter the poultry house.
  7. When they leave the house, a reversed process must be followed.

Still more needs to be done to prevent the entrance and spread of disease.

Separate materials for each house

For each house, separate materials must be used, keeping a dedicated set of tools and equipment necessary for daily work.

Very important: no materials should be moved from one house to another unless thoroughly disinfected. Crates for bird transport in the case of thinning (partial depopulation of a broiler flock) are an important example.

Practice clean disposal of mortality

First, dead birds’ removal must be frequent (minimum twice a day) as carcasses are a source of infection. The next point is to make sure the route of birds’ disposal is strictly unidirectional, and the buckets or wheelbarrows for the transport of the dead birds do not reenter the poultry house. Finally, the carcasses should remain outside the farm or as far from the buildings as possible until collection, incineration, or composting.

2. Broiler house management

After the general organization on the farm, let’s move on to the poultry houses.

Cleaning and disinfection of the house are the first steps – and check their efficacy!

Cleaning and disinfection are essential components in preventing the persistence and spread of pathogens. Both together aim to decrease microbial numbers on surfaces (and in the air) to a level that will ensure that most -if not all- pathogens and zoonotic agents are eliminated.

Cleaning refers to the physical removal of organic matter and biofilms, so the microorganisms and pathogens are afterward exposed to the disinfectant.

For effective cleaning and disinfection, the all-out/all-in system has proven of value. When birds are collected, all organic material, including feed residues and litter/feces, is removed.

Effective detergents and hot water are used to remove any grease or organic material. Pay special attention to the floors! Also, all surfaces and equipment should be sufficiently cleaned and given final disinfection.

Cleaning is crucial

A study by Luyckx and collaborators (2015) revealed that the mean total aerobic bacterial count on swab samples taken in broiler houses decreases significantly already after cleaning (figure 2). Good cleaning not only strongly reduces microbiological contamination and organic material but also ensures that the subsequent disinfection has a stronger impact on the remaining microorganisms. Consider that all disinfectants, even in high concentrations, are barely effective in the presence of organic material.

reduction of bacteria on surfaces after cleaning and after cleaning and disinfection

Figure 2: % of reduction of bacteria on surfaces after cleaning and after cleaning and disinfection (adapted from Luyckx et al., 2015)

Keep an eye on cleaning & disinfection efficacy

After cleaning and disinfection are complete, it is good practice to check the floors for Total Viable Count (TVC), Salmonella, and E. coli to test the efficacy of the cleaning and disinfection process. Recommended levels of TVC should be less than ten colony forming units per square centimeter (CFU/cm2), and E. coli and Salmonella levels should be undetectable.

When high TVC are found, the cleaning and disinfection procedure must be evaluated, including the products (a rotation is recommended) and their application (e.g., dosage, dilution, water temperature, and exposure time). Also, possible reinfection by vermin or personnel during the downtime must be controlled.


After cleaning and disinfection, a down-time time of 10 days allows disease-causing pathogens to die (UC Davis, 2019).

Cleaning and disinfection of the waterline against biofilm

In the waterlines, the build-up of biofilms can be an issue. Biofilm is a sticky film that can be found inside water lines, regulators, and nipple drinkers. It starts when bacteria attach to a surface and produce a matrix of extracellular polymeric substances (EPS), including proteins and sugars, giving the biofilm the stickiness that traps other bacteria and organic matter. It provides the bacteria with protection from the external environment, and thus they multiply and thrive.

Biofilms not only block the water flow, but they can also include pathogenic bacteria. Thus, the waterline must be regularly cleaned and disinfected, not only between flocks but also within each flock.

waterline in biofilm

Between flocks, an effective waterline cleaning should include:

  • Application of hydrogen peroxide at high concentration, leaving it in the system for 24-48 hours to remove the biofilm from the pipelines)
  • Flush the line to remove the detached biofilm, also activate the nipples with a broom or stick to flush them
  • Immediately before the placement of the new chicks, the water lines should be flushed to have fresh drinking water available to the chicks
  • The water pressure must be adjusted so that a droplet of water is visible at the end of each nipple, and the drinkers are put to the correct height to stimulate water intake and avoid spilling

During the life of the birds, a water disinfectant should be used to prevent biofilm formation, e.g., hydrogen peroxide in weekly applications or the continuous use of chlorine. Also, flushing is a good practice during the whole cycle to make sure that biofilm is removed and the birds count with fresh drinking water.

To a certain extent, biofilm build-up can be prevented by using organic acidifiers in the water, which improves the sanitizers’ effectiveness and reduces bacterial growth in water lines.

Correct ventilation helps to prevent respiratory diseases

To keep broilers healthy, providing optimal ventilation in the poultry house is crucial. CO2 and temperature are the most critical parameters. CO2 should never exceed 2500 ppm and should be monitored continuously, most notably in the early morning before birds increase activity (e.g., eating). Ventilation rates should be adjusted to keep CO2 below this limit. Draught or cold spots resulting in uneven distribution of birds in the house should be avoided, and causes should be investigated and repaired immediately.

Incorrect ventilation often is the reason for respiratory diseases and the need for antibiotic treatment. No matter if natural or power ventilation is used, proper monitoring of the system is indispensable to ensure the well-functioning of the equipment and, therefore, appropriate air quality (Neetzon et al., 2017).

Litter management to keep diseases in check

Effective litter management is another step on the road to keeping the birds healthy. Dryness of litter and ammonia level at bird’s level are two significant key success factors in raising broilers. Dry litter preserves the footpads, so litter material should have a good moisture-absorbing capacity (e.g., chopped straw, wood shaving, rice husks, sunflower husks). When using build-up litter, litter sanitation and treatments need more attention.

Litter treatment (with acidifying or binding substances) and adequate ventilation are the most practical measures to control ammonia and improve littler quality (Malone, 2005). Keep litter temperature at 28 – 30°C (82.4 – 86°F), and use only litter tested or certified to have a TVC <10 CFU/g.

3. Flock management

The basis: healthy, high-quality day-old chicks

To produce good-quality day-old chicks, the parent flocks (PS) must be of good health status. PS should be free from vertically transmitted diseases such as Mycoplasma and Salmonella and be vaccinated/protected against important diseases:

  • Salmonella pullorum/Salmonella Gallinari should be assessed in PS by RPA serology in week 25-30, at least 60 samples per flock.
  • Mycoplasma gallisepticum should be checked by RPA/ELISA serology on a regular basis, preferably at least monthly, with a minimum of 30 samples per flock.

Parent flock vaccination leads to the production of maternal antibodies that help prevent horizontal infection (from the broiler farm environment) in chicks at an early age. This type of prevention is the primary function of some vaccinations, such as against Gumboro disease.

An essential part of the broilers’ life occurs already in the hatchery. Single-stage incubation is recommended, and all floor eggs and dirty nest eggs should be excluded to assure the best day-old chick quality.

Comfortable conditions bring chicks to eat

The brooding phase needs special attention; it is about welcoming the chicks and making them comfortable in the house environment. For this, enough litter needs to be provided, the environment must be managed, and feed and water must be supplied.

At least 24 hours before chick placement, the house and floor temperature are increased to a minimum of 34°C and 28°C, respectively. Proper ventilation and lighting are also essential. These conditions need to be monitored and adjusted after the placement so the chicks feel comfortable and start feed and water consumption. Checking chick behavior is crucial during the first hours after placement.

Upon the placement of the chicks, it is recommended to have pre-starter crumble feed available on top of brooder paper underneath the drinking line. To stimulate early feed and water consumption, gently place the chicks onto that paper. The target is to have 100 % of chicks with crop filled within 48 hours of chick placement.

Reduce the stocking density

chickens feeder In general, high stocking density may restrict bird movement, interfere with airflow, and increase litter moisture and microbial growth, including pathogens, which potentially impairs broiler health, welfare, and performance.

When reducing antibiotics, increase the space per bird by 0.05 ft2/46 cm2 per bird compared to your current conventional program. A lower stocking density helps keep litter moisture at a minimum, which reduces the shedding of cocci oocyst and pathogenic bacteria over the population.

Feed and water access must be granted to all animals at every moment. The number of chickens per feeder or drinker depends on the type of equipment used.

Consistent observation of the flock

To recognize emerging health issues, producers should critically observe the behavior of birds every day. On which points should they focus?

  • First, when entering the house, birds’ behavior and response to the poultry worker should be observed with attention. Note the spread of birds throughout the house.
  • Note birds’ drinking and eating behavior. Feed and water intake should be recorded daily, always at the same hour.
  • The quality of the fresh fecal droppings should be judged. Any changes in the fecal droppings (loss of consistency) can help notice emerging disease and take measures against it.

Especially during and after feed change, attention to changes in the usual feces consistency is necessary.

Vaccination and judicious antibiotic use are crucial

Carefully consider vaccination programs for broilers. Unnecessary vaccinations impact the immune system, possibly resulting in reduced performance and, in some circumstances, make the birds more susceptible to other diseases. Hence, the vaccination program must be diligently attuned (Neetzon et al., 2017).Vaccination and judicious antibiotic use are crucial

  • The disease background of the parent farm as well as the broiler farm where the chicks will be placed are essential factors for the vaccination program
  • If possible, vaccine strains that are the least immunosuppressive should be chosen
  • If coccidiostats are not permitted, an effective vaccination against coccidiosis is required and must be done as early as possible
  • All vaccinations must be given using a standard operating procedure that minimizes bird discomfort and optimizes the vaccine, and always administer vaccines following the advice from the manufacturer

After the vaccination, it is essential to monitor the effects of vaccination stress and take preventive measures to avoid any issues with broiler performance in terms of weight gain and mortality.

Use antibiotics with discernment

As we aim to reduce antibiotics, they should be limited to pure therapeutic use, only if other disease-prevention measures have not been successful, and mortality or disease symptoms make the treatment necessary. Before the treatment, the disease must be diagnosed by a qualified veterinarian. The diagnosis should be preferably followed up by isolation of the disease-causing bacteria, classification, and susceptibility testing before the antibiotics are applied.

Small-spectrum antibiotics that are less likely to cause antimicrobial resistance (AMR) should be preferred. Broad-spectrum antibiotics or antibiotics that are likely to cause AMR can only be used after susceptibility testing has demonstrated resistance to a first-choice antibiotic. The treatment effect must be evaluated by daily monitoring of disease symptoms, mortality, water, feed intake, and body weight gain.

Thinning – things to consider

If thinning (partial depopulation) is practiced, it should be done with the highest bio-security measures. Producers must ensure that the equipment used in the catching process is thoroughly cleaned before entering the house, and bird-catching personnel takes the same measures as farm personnel when entering the farm and the house. These policies will help to minimize the introduction of infectious agents.

Keep the feed withdrawal period for this process as short as possible to avoid flightiness, which can induce skin lesions (some regions catch birds in low light intensities to avoid flightiness). A short feed withdrawal period also prevents over-consumption of feed in a short amount of time, possibly disrupting feed passage in the gut and leading to bacterial imbalance and dysbacteriosis in the remaining birds. After thinning, feed and temperature must be adapted to the lower number of animals.

Provide your birds with high-quality water for drinking

Provide your birds with high-quality water for drinkingWater is the most important nutrient for broilers. It plays an essential role in digestion and metabolism, thermoregulation, and waste elimination.

Several factors affect water quality: temperature, pH, bacteria, hardness, minerals, and total dissolved solids. These parameters should be analyzed at least twice per year. If necessary, corrective actions should be taken, e.g., a filtration to remove minerals, the addition of chlorine for disinfection, or the addition of organic acids to drop the pH.

Before each cycle, the water must be tested for total aerobic + enterobacteria, compared to reference values: Total plate count (TPC) should be < 1000 CFU/ml, and E.coli, Enterobacteriaceae, yeast, and molds at undetectable levels. The section about cleaning and disinfection of the waterline provides insights and practical advice about water sanitation and microbiological analysis.

Nutrition & feeding – a pillar for antibiotic reduction

Nutrition and feeding in ABR broiler production are not only about providing nutrients for growth but also about the effects of the feed on gut health. Gut health is essential for animals’ overall health, welfare, and productivity, even more so in antibiotic reduction scenarios.

Feed should be of the highest quality – in all respects

High feed quality is necessary to provide the animal with the required nutrients and achieve their optimal utilization. Also important is the absence, limitation, or management of harmful substances and pathogens. High quality, therefore, includes:

  • Form and composition of the final feed
  • Nutritional value of the raw materials
  • Management of harmful substances.

From reception and storage of the raw materials to the dispatch of the finished feed, the feed mill management emphasizes their quality assurance system, which is decisive in this connection.

First measure: quality assurance at the feed mill level

The feed mills producing for operations with no or reduced use of antibiotics must have a quality assurance (QA) and/or a good manufacturing program (GMP) in place that guarantees the production of consistently good quality feeds.

Proper raw material management and processing of feeds are necessary to achieve the lowest possible microbial-pathogen load, including:

  • An effective rodent and wild birds control
  • Disinfection of all the vehicles entering the feed mill
  • Proper storage and utilization of raw materials (e.g., first in-first out use, silo management)
  • Periodic thorough cleaning of milling equipment, premises and storage areas, and the monitoring of these activities
  • Standard operating procedure and quality assurance systems that guarantee feed safety and quality
Check the quality of the raw materials and the final feed

Digestion, absorption, and gut health depend on the quality of the feed ingredients. To provide the best preconditions for healthy growth, producers should avoid raw materials of a reduced and/or inconsistent quality. For this purpose, each raw material batch should be analyzed for its specific quality parameters. Quality parameters to consider are:

  • Physical ones, such as color, odor, particle size, and general appearance
  • Chemical ones, such as nutritional composition and specific parameters. For example, grains should be analyzed for mycotoxins and antinutritional factors; fats and oils need to be analyzed for free fatty acids (FFA), unsaturated/saturated (US) ratio, iodine value (IV), but also the peroxide value (PV) as oxidized fats have a lower energy value, and their intake is related to enteric diseases
  • Biological ones, including yeasts, molds, and enterobacteria

Also, the finished feed should be monitored by analyzing every batch concerning composition compared to values in the feed formulation, as well as physical, chemical, and microbiological quality parameters.

Clean storage on the farm prevents feed spoilage

As in the feed mill, keeping the farm facilities clean is of the highest importance. Warehouses, silos, bins, feeders, etc., should be emptied, cleaned, and disinfected after each flock; this avoids the formation of feed aggregates that can lead to mold growth and mycotoxin contamination; also, insects, bacteria, and parasites can remain in those residues.

Green field and factory

Adapt feed formulation and feeding to the feeding phase

The value of phase feeding

Having the correct number of dietary phases to meet animal demands and avoid excess nutrients provides better intestinal health and thus aids production animals in ABR scenarios. The feeding phases should be designed to prevent abrupt changes in nutrition and raw material inclusions, possibly leading to dysbacteriosis.

Feeding for gut health

When feeding broilers in antibiotic reduction scenarios, extra care should be taken when formulating diets. The challenge is to achieve the same performance as conventional management at an optimum cost.

  • Don’t waste nutrients: Improve feed digestibility, and at the same time, reduce the dangers of antinutritional factors coming from different ingredients by using suitable exogenous enzymes.
  • Keep an eye on fiber: Moderate levels of insoluble fibers with adequate structure and composition can be included to promote gizzard development and function. This measure leads to a better modulation of gut motility and feeds passage into the intestine. Additionally, it promotes gut health, resulting in higher nutrient digestibility.
  • Be careful with protein: Excess of undigested protein in the hindgut may lead to the proliferation of Clostridium perfringens; then, subclinical challenges of necrotic enteritis may occur. Moreover, the excess of nitrogen may increase feces moisture content, leading to wet litter. The optimization of the diets based on digestible amino-acid profiles and the use of synthetic amino acids decrease or eliminate the minimum requirements of crude protein, avoiding its excess.
Which feed form?

The feed form depends on the age or feeding phase: starter feeds can be offered as coarse mash, but preferably as crumble or mini-pellets (< 2 mm diameter) and grower and finisher diets as 3 – 4 mm pellets.

When using pelleted diets, quality is also the most crucial criterion. Poor pellet quality and thus the excess of fine particles increase feed passage rate, resulting in poor gizzard development and compromised gut health.

A high-quality pelleted feed can withstand – without much breakage – the handling that occurs after processing, such as transportation, storage, and farm management. Pellet quality can be measured by the Pellet Durability Index (PDI) obtained by simulating the impact and shear forces in a known quantity of feed for a determined amount of time. After this time, the sample is sieved, and the fines are separated, weighed, and compared with the initial sample

The PDI should be measured in the feed mill and compared to a standard. Later, it is also recommended to measure the PDI on the farm, and the producer should take corrective actions if the pellets cannot maintain their quality.

Additionally, it should be known that coarse ground grains stimulate gizzard development and function. So, about 30 % of the feed should consist of particles between 1-1.5mm (post pelleting) in all feeding phases.

Broilers’ selection criteria for feed are form, color, size,
and consistency

Broilers’ selection criteria for feed are form, color, size, and consistency

Broilers’ selection criteria for feed are form, color, size, and consistency. They prefer feed that is easy to pick, such as crumbles or pellets. 

Feed additives can support antibiotic reduction

The feed additive industry provides broiler farms and integrations with various solutions to make production more manageable and efficient.

A healthy start is half the battle

Let’s start with the chicks. The early introduction of beneficial bacteria into the intestinal tract has proven helpful for gut health optimization. This colonization can be achieved with the administration of suitable probiotics preparation at the hatchery. Multi-strain probiotic preparations effectively initiate healthy microbiome development for optimum gut health. For these challenges, support is offered through EW Nutrition’s VENTAR D and ACTIVO LIQUID, phytomolecule-based products for the feed and the waterline, respectively.

Maintain gut health

Gut health is one of the essential preconditions for efficient growth. Only a healthy gut guarantees efficient digestion and absorption of nutrients. Several approaches are recommended to maintain gut health:

  • Promotion of beneficial and reduction of pathogenic gut flora: here, solutions can come in the shape of products based on phy­tomolecules that can be applied with the feed (VENTAR D) or the water (ACTIVO LIQUID)
  • Management of bacterial toxins and mycotoxins: for this topic, products mitigating the toxins’ negative impact on the birds (Product range of MASTERSORB and SOLIS) are offered

Protect your feed

When feed is stored, there is always the risk of bacteria, mold, or yeast overgrowth. Oxidation of feed ingredients, such as fats and oils, reduces their nutritional value. These issues can be prevented by applying:

  • Acidifiers that have antimicrobial effects due to their pH-decreasing effect, which, later on, improves the feed digestibility and stabilizes the GIT flora (ACIDOMIX, FORMYCINE, and PRO-STABIL)
  • Antioxidants preserving ingredients susceptible to oxidation, such as fats and oils (AGRADO, SANTOQUIN, and STABILON)

Improve pellet quality

Moisture retention during the conditioning process influences pellet quality: higher moisture retention entails a higher starch gelatinization resulting in higher digestibility, pellet binding, fewer fines, and a higher PDI. Surfactants (for example, SURF•ACE) are compounds that can reduce the surface tension between the water and the feed, improving moisture absorption during the conditioning process.

Besides that, moist steam in the pelleting process penetrates better and has a higher antimicrobial effect leading to lower production of bacterial and mycotoxins. The possible reduction of the pelleting temperature protects the nutrients.

ABR in broiler production is practicable – by observing some rules

As shown above, antibiotic-reduced broiler production needs many aspects to be considered and a lot of measures to be taken. All of these measures seek to keep animals healthy and avoid antibiotic use. Maintaining gut health is crucial, as only a healthy gut performs well, achieves the optimal utilization of nutrients, and increases growth performance.

Maintaining a successful production unit with no or reduced antibiotic use requires a holistic approach in which best practices must be assured at all levels of the production chain. The feed additive industry provides a broad range of solutions to support animal production through this challenging task. The objective could not be more critical: lowering antibiotic resistance to assure the future of animal and human health.



Davies, Robert, and Andrew Wales. “Antimicrobial Resistance on Farms: A Review Including Biosecurity and the Potential Role of Disinfectants in Resistance Selection.” Comprehensive Reviews in Food Science and Food Safety 18, no. 3 (2019): 753–74.

Dewulf, Jeroen, and Van Filip Immerseel. “General Principles of Biosecurity in Animal Production and Veterinary Medicine.” Essay. In Biosecurity in Animal Production and Veterinary Medicine: From Principles to Practice. Wallingford, Oxfordshire, UK: CABI, 2019.

Luyckx, K.Y., S. Van Weyenberg, J. Dewulf, L. Herman, J. Zoons, E. Vervaet, M. Heyndrickx, and K. De Reu. “On-Farm Comparisons of Different Cleaning Protocols in Broiler Houses.” Poultry Science 94, no. 8 (2015): 1986–93.

Kreis, Anna. “Broiler Feed Form, Particle Size Assists Performance.” Feed Strategy, September 20, 2019.

Malone, B. “Litter Amendments: Their Role and Use.” University of Delaware – Agriculture & Natural Ressources – Fact Sheets and Publications. University of Delaware, November 2005.

Neetzon, A. M., Pearson, D., Dorko, N., Bailey, R., Shkarlat, P., Kretschmar-McCluskey, V., Van Lierde, E., Cerrate, S., Swalander, M., Vickery, R., Bruzual, J., Evans, B., Munsch, G., & Janssen, M. (2017, October). Aviagen Brief. Aviagen – Information Library.

UC Davis Veterinary Medicine. “‘All out All in’ Poultry Management Approach to Disease Control. A Guide for Poultry Owners.” Poultry-UC ANR, March 2019.


The 3 critical factors for successful pigmentation

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By Predrag Persak, Regional Technical Manager, EW Nutrition

We eat with our eyes. Depending on our cultural background and our experience, we prefer foods that have a certain appearance. Moreover, we regulate our taste and health expectations based on this appearance. In that equation, color plays an essential role. Think of healthy-looking salad, fruit, eggs, meat, and more. Certain foods are more appetizing and appear healthier – and, in many cases, are indeed so – when they display a certain color.

For poultry producers,  skin color and the yolk color of table eggs are of major concern. This concern is driven by the market (in certain regions,  skin and yolk pigmentation heavily affect buying preferences), by regulations, and by an interest in using all options to increase product quality with natural solutions.

critical factors for successful pigmentation


Where does poultry pigmentation come from?

Birds cannot synthesize pigments; they must take them up with their feed. Natural pigments have, besides their pigmenting properties, an antioxidant role in the bird’s organism. Unfavorable conditions can heavily influence the outcome of pigmentation. For producers looking to achieve reliable and consistent coloration, results are often unpredictable and disappointing.

Knowing the factors that affect pigmentation will help us to better understand how to achieve the desired level of pigmentation – or to identify, in hindsight what went wrong and when. In general, three different factors are decisive for efficient pigmentation:

  1. The quality of the product (type, content, and stability of the pigment)
  2. The amount of pigment ingested/absorbed/deposited
  3. The persistence of the pigment in the final product

1. Product quality is essential

The first point to be considered is the quality of the product you use, including type, content, and stability of the pigment in the product and the feed.

Content and quality of active substances determine efficacy

Concerning type and content, what matters more than the total amount of carotenoids is the level of active substances. The trans-isomers have higher efficiency than the cis-isomers and are decisive for pigmentation.

Natural pigments originate from natural sources that often vary due to growth conditions, harvest, and handling. Therefore, producers need to control incoming materials and conduct proper formulation during the production process. This is crucial in order to obtain an adequate level of pigments for appropriate pigmentation.

Adequate measures ensure the stability of the pigment in the product

Natural pigments are sensitive to light and air; they are easily oxidized. Also in the feed formulation there are many substances (e.g. oxidized forms of trace elements, choline, chloride) enhancing the oxidation of the pigments. Some precautions can be taken to protect natural pigments from oxidation:

  • Use of adequate package materials preventing the exposure to light and air
  • Use of antioxidants in the product as well as in the feed formulation

With these measures in place, the pigments are given adequate protection to ensure their stability.

2. Pigment intake, absorption, and deposition affect pigmentation

Every factor reducing the amount of pigment reaching its target deteriorates the quality of pigmentation. Below are the crucial factors producers need to take into account.

Feed intake is correlated to pigment intake

Assuming that the pigment is homogeneously distributed in the feed, feed intake directly determines the intake of pigment. Consequently, anything that affects feed intake also affects pigment intake and pigmentation. To that end, what is also decisive is particle size and homogeneous distribution of the pigment in the product.

The energy concentration in the feed is also a critical factor. Antinutrients, unpleasant taste, or inconsistent feed structure negatively influence feed intake.

Feed intake is also influenced by other elements:

  • the animal’s health status
  • environmental conditions
  • the availability of water
  • the housing system (free-range, farm)
  • feeding management factors (length of the feeding lines, separation of the feed in silo bins or through the feeding lines etc.).

Saponification plays a role in pigment absorption

Through saponification, the natural, esterified form of the pigment gets broken down and the pigment is separated from the fatty acid molecule. This step is necessary to enable the pigment to pass the intestinal wall. The higher the saponification, the better the bioavailability of the pigment.

Besides improving bioavailability, saponification also influences the particle size and the homogeneous distribution of the pigment particles in the product.

Some feed materials and nutrients influence pigment absorption

If pigments are used, it is essential to know that some feed materials or nutrients have a beneficial or adverse effect on the absorption or deposition of the pigments. The inclusion of saturated, low-digestible fats or fat sources decreases pigment absorption and, therefore, the efficacy of pigmentation, whereas unsaturated fats (oils) facilitate it. The addition of oil up to 5% linearly increases pigment deposition in the egg.

Nutrients such as Calcium or Vitamin A also change pigment absorption. In the case of calcium, the level and the source are decisive. High levels of fast soluble limestone or calcium levels higher than 4 % will decrease the absorption. Also, increased levels of Vitamin A are critical for the effectiveness of deposition, as Vitamin A and the pigment use the same transporters. This fact is very important in broilers if vitamin A addition is applied through the water.

Mycotoxins affect feed intake and absorption

Mycotoxins affect feed intake and absorption

The presence of mycotoxins in feed, especially DON, will reduce feed intake due to the bad taste. The gut health-impacting effect of the mycotoxins will increase the passage rate of the feed and will prevent adequate absorption through the intestinal wall. Additionally, the liver function is negatively impacted by the mycotoxins. This results in an affected serum transport and a lower storage capacity for the pigments, leading to lower deposition in the tissue.

Impacted gut health is bad for pigmentation, too

Good gut health is essential for good pigmentation, including the uptake/absorption of pigments, their deposition, but also already existing pigmentation. All health challenges that negatively affect digestion and absorption, such as dysbiosis, negatively influence pigment availability and pigmentation. In such cases, products or strategies improving digestibility and gut integrity can be a solution.

Specific diseases such as NCD, Coryza, helminthiasis, as well as coccidiosis are an important consideration. The first three diseases lower pigment deposition; coccidiosis, however, has multiple impacts. It not only affects digestion and absorption and, therefore, the ongoing pigmentation but also decreases the already existing one.

Coccidia cause damage to the intestinal wall and affect its activity, resulting in a lower absorption. Additionally, the animals lose weight due to an insufficient supply of energy. The consequence is a degradation of fat tissue where the pigments are stored. Furthermore, coccidiosis means oxidative stress for the animal – triggering a reaction of the organism. As pigments also serve as antioxidants, they are removed from the fatty tissues and used as antioxidants.

Within three days post-infection, pigment levels in the subcutaneous tissues, but also in the serum and the liver, drop to 0. Coccidiosis outbreaks occur more frequently in alternative housing systems, affecting broilers, but also laying hens. Paying close attention to coccidiosis and having a proper anticoccidial program in place is obligatory for good pigmentation.

3. Pigmentation ends when the final products are on the shelf

For the end consumer, an attractive color in the final products (such as pasta or the broiler carcass) is essential. Producers of these final products request to put more pigments into the feed, but is this always the solution? As described before, there are a lot of factors possibly impacting the process of pigmentation during animal production on the farm.

However, also in the pasta factory or in the slaughterhouse, pigmentation of the final products can be impacted. In the pasta factory, oxidizing enzymes can destroy the pigments making the pasta pale and unattractive. If they have issues with Salmonella in the slaughterhouse, the birds may be scalded in slightly hotter water. The defeathering afterward can cause the loss of the upper layer of the skin with the pigments.

These examples show why pigmentation is not just the responsibility of the animal producer, but rather continues up to the moment when the pasta or meat is ready for the consumer.

Control these 3 factors for best pigmentation results


Pigmentation is a dynamic process that requires knowledge and attention. The better we control the influences, the more consistent and predictable the outcome. To that end, it is essential to use the product with the best quality, the best amount of pigment that can be not just ingested, but also absorbed and deposited, and with the best persistence in the final product and along its shelf life.

Keeping everything under control is not always possible or is extremely difficult. That is why choosing the right product is a vital link that will allow us to pay more attention to those things that we can find difficult to manage.

To meet all these demands, Colortek Yellow B is the best natural yellow pigment on the market. This highly concentrated natural yellow evidences optimal flowability, homogeneous mixing in feed and high stabilit, for reliable and consistent results. In addition, it boasts high bioavailability and is produced in the EU in a state-of-the art facility, with FAMI-QS certification and strict control of undesirable substances.

How to develop phytogenic feed additives

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by EW Nutrition Phytogenics team

Modern feed additives are now commonly used as a critical tool to improve animal health. Among these, phytogenic feed additives are increasingly widely adopted. Consequently, more and more products are entering the market, leaving producers to wonder how these products differ from one another and which product performs best. To better understand the benefits that phytogenic feed additives can bring to operations, one must understand the development process feed additives undergo.

develop phytogenic feed additives for chicken

Not all feed additives are born equal

Feed additives are products that are added into an animal feed to improve its value. They are typically used to improve animal performance and welfare and consequently to optimize profitability for livestock producers.

Their purpose should not be confused with that of veterinary drugs. Feed additives provide additional benefits beyond the physiological needs of the animals and should be combined with other measures to improve production efficiency. Those measures include improvements in management, selection of genetics, and a constant review of biosecurity measures.

Several categories of feed additives exist. They all have in common that they are mixed into the feed or premix or the drinking water in relatively low inclusion rates to serve a specific purpose. Examples of feed additives are organic acids, pre- and probiotics, short and medium chained fatty acids, functional yeast products, and phytogenic feed additives. Modern feed additives also blend those different additives into combination products, increasing the value of the final products.

Phytogenic feed additives are a sub-category of additives containing phytomolecules, active ingredients which originate from plants and provide a unique set of characteristics. These molecules are produced by plants to protect themselves from molds, yeasts, bacteria, and other harmful organisms. Depending on the type of molecule, phytomolecules have different properties, ranging from antimicrobial to antioxidant and anti-inflammatory.

EW Nutrition’s approach to developing Ventar D: 6 steps

The development of best-in-class phytogenic feed additives is a complex process. For Ventar D, EW Nutrition divided the process into the following steps, which can serve as a template for a successful development process:

  1. Reviewing customer needs
  2. Active ingredient selection
  3. Technical formulation
  4. Application development and scale-up
  5. Performance tests
  6. Safety and regulatory validation

Understanding customer needs

The most important point in developing a feed additive is customer-centricity. Understanding the challenges and needs of producers is crucial to developing feed additive solutions.

In a first step, additive producers need to evaluate and quantify customer needs wherever possible. This is achieved through communication and literature review: Producers, key opinion leaders, and research partners are interviewed, and their challenges are listed. In the next step, those challenges are further analyzed using scientific literature. In a final step, the customer needs are ranked according to their impact on the customer’s profitability.

customer needs

Subsequently, the minimum requirements for the new feed additive are derived. For phytogenic feed additives, this might be, for instance, something like “Improving animal performance and reducing antibiotic use while increasing profitability”. The selected key performance parameters might be, for example, feed efficiency improvements in broilers.

Marketing Research

Meeting unmet needs

Once the customer needs have been understood, the next phase of the development starts. Based on the intended mode of action, certain phytomolecules are chosen based on their described properties. In our example, this might be an antimicrobial mode of action that targets enteropathogenic bacteria in broilers, supporting gut health.

Meeting unmet needs

In this in-vitro process, the selected individual compounds will be tested for their respective antimicrobial efficacy using MIC and MBC testing. Those tests are run using high-purity compounds.

features test

The tests will be conducted using various relevant field strains like E. Coli, S. enterica or C. perfringens. In the next step, the testing will be repeated with commercially available ingredients. The most promising compounds will be tested in more complex mixtures.

Modern phytogenic feed additives are based on the concept of combining different phytomolecules to attack bacteria in diverse ways, with their antimicrobial effects being multi-modal. This mode of action is crucial because it makes it very unlikely that bacteria can develop resistance to combinations of phytomolecules, as they do to antibiotics.

Selecting the right form of application

Feed processing is often a challenge for additives. Many phytomolecules are highly volatile and prone to volatilization and high temperatures. Especially non-protected phytogenic products are negatively affected by high pelleting temperatures and long retention times of the feed in the conditioner. The results are losses in activity.

features test

Therefore, the development of appropriate delivery systems is a preemptive method to ensure the release of the effective compounds where they should be released – in the gut of the animals. Those delivery systems can utilize emulsifiers when applying the additive via the water for drinking, or encapsulation technologies when the new additive is administered via feed.

Due to the importance of mixability, flowability, and pelleting stability for the performance of the feed additives, the exact types of emulsifiers, carrier, and technologies used in their production is often considered corporate intellectual property.

The importance of in-vivo evaluations

In one of the last steps of the development, the newly developed feed additive prototype needs to prove its safety and efficacy in the animal. Hence the need to run evaluation studies to confirm the mode of action chosen in the initial lab phase. Typically, the additive will be tested in the target species in in-house and external research institutes.

farm test

For a phytogenic feed additive, that might entail comparing its effect on body weight gain, feed efficacy, and gut health against different control groups. Additionally, the newly developed feed additive might be compared to existing additives to get a better understanding of its capabilities.

safety test

Dose-finding studies are conducted to verify the chosen dose recommendation and additional overdosing studies are conducted to prove the safety of the additive for both animals and consumers. In certain markets or regulatory environments, additional studies might be required. Those can contain environmental safety assessments or proof that the new additive does not create residues in animal products.

Case study: Ventar D

For Ventar D, the process followed these steps meticulously, in agile iterative development loops that went from the customer need to formulation, testing, scale-up, in-house and external trials, and finally production.

These steps ensured that the final product that reaches the customer’s doorstep delivers on the expectations – and more.

Case study: Ventar D  

Choose your phytogenic products wisely

The plethora of (phytogenic) feed additives in the market leaves producers with many options to choose from. However, only scientifically developed feed additives can be relied upon to optimize both animal health and production profitability. It is important to select reliable feed additive producers who developed their phytogenic product with the customers’ challenges in mind and went through all the steps necessary to create a high-performing and safe additive.

Phytogenic additives: An ROI calculation

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By Ruturaj Patil, Global Product Manager – Phytogenics, EW Nutrition

Global trade in agricultural products has a direct impact on the added value in regional broiler production. Due to fluctuating meat and feed prices, a tight profit margin can melt away quickly. Changes such as the use of cheaper raw materials, implemented to deal with reduced margins, may negatively affect flock health, creating a vicious cycle: If the flock also experiences increased disease pressure, the financially critical situation worsens.

Phytogenic additives: An ROI calculation

What can the right phytogenic feed additive deliver for broiler producers?

It is essential to improve broiler gut health, as only healthy birds will perform and allow producers to be profitable. Producers can maintain flock performance through preventive management measures, a consistent hygiene concept, and the use of high-quality feed. For unproblematic flocks, the same measures also positively affect profit, generating a healthy return on investment (ROI).

What affects your return on investment?

In broiler production, the cost of feed is highest, with a share of 60 – 70 % of the total production costs. The proportion tends to be higher in markets that rely on importing feed raw materials (Tandoğan and Çiçek, 2016).

Let us take an example: With a compound feed price of 300 € / t as the basis, an increase of 10 € / t results in a profit reduction of 0.016 € / kg live weight. On the other hand, an improvement in feed conversion from 1.60 to 1.55 results in a financial advantage of 0.015 € / kg live weight. The best possible feed efficiency is always desirable to keep production costs low.

Another risk factor for high-yield broiler production lives in the poultry intestines: the most significant “invisible” losses result from subclinical necrotic enteritis (Clostridium perfringens). This disease worsens the feed conversion on average by 11 % (Skinner et al., 2010). In the previous example, this would reduce feed efficiency from 1.60 to 1.78 points and reduce the contribution margin by 0.054 € / kg live weight. In addition,  a live weight reduction of up to 12 % can be observed (Skinner et al., 2010). It is, therefore, critical to stabilizing gut health to reduce the risk of subclinical necrotic enteritis.

Practice prevention for a secure return on investment

The prophylactic use of antibiotics in compound feed was a well-known reality for decades. With the EU-wide ban on the use of antibiotic growth promoters, the occurrence of multi-resistant bacteria, and a globally increased demand for antibiotic-free chickens, producers now have had to cut down on antibiotic use.

For this reason, a lot of research has been conducted into alternative measures for maintaining good broiler health. Studies have confirmed that setting up a comprehensive hygiene concept to reduce the formation of biofilms on stable surfaces and reduce the recirculation of pathogens is a solid basis. At every production stage, irregularities can be detected through a meticulous control of performance parameters and illness symptom-centered health monitoring. Diseases can either be avoided or at least recognized earlier through targeted measures, and treatment can be carried out more efficiently.

broiler performanceA thorough hygiene concept and careful monitoring at every production stage are key to ensuring broiler performance.

Feed additives for intestinal stabilization

Hygienically impeccable compound feed is the wish of every animal producer to promote the development of a balanced intestinal flora. However, the quality of the available raw materials is subject to fluctuations and can therefore not be 100 % anticipated. Consequently, producers are now commonly balancing these uncertainties by using feed additives, which positively influence the intestinal flora. These products must prove their positive effects in scientific studies before they can be used in practice.

An effective solution: Encapsulated phytogenic feed additives

Studies have found that certain phytomolecules, which are secondary plant metabolites, can support broiler gut health. By stimulating digestive enzyme activities and stabilizing the gut microflora, feed utilization improves, and broilers are less prone to developing enteric disorders (Zhai et al., 2018).

The encapsulation of these naturally volatile substances in a high-performance delivery system is critical for the success of a phytogenic feed additive. This protective cover, which is often a simple coating, provides good storage stability in many cases. However, in addition to the high temperatures, mechanical forces also act on these coatings during pelleting. The combination of pressure and temperature can break the protective coating of the product and lead to the loss of active substances.

A complete solution: How Ventar D maximizes your ROI

Because of the difficulties mentioned, the use of modern delivery system technologies is therefore necessary. EW Nutrition has many years of experience in the development of phytogenic products. Due to an original, innovative delivery system technology, Ventar D can offer high pelleting stability for optimal improvement of animal performance.

In particular, the positive influence of the phytogenic feed additive Ventar D on intestinal health under increased infection pressure was assessed in multiple studies. In two studies carried out in the United Kingdom, birds were challenged by being housed on used litter harvested from a previous trial. Moreover, increasing levels of rye were introduced into the diet, adding a nutritional challenge to provoke an increased risk of intestinal infections in the broilers. The use of 75 g of Ventar D per t compound feed increased the EPEF (European Production Efficiency Factor) by 4.1% and feed efficiency from 1.63 to 1.60.

A complete solution: How Ventar D maximizes your ROI

With Ventar D use at 100 g / t compound feed under comparable conditions, EPEF increased by 8.9 %, and feed efficiency improved by 5 points (0.05), compared to a non-supplemented control group (NC).

Another study was carried out in the USA. In addition to performance parameters, data on intestinal health were also recorded. In the group fed with Ventar D (100 g / t compound feed), 50 % fewer necrotic enteritis-related lesions of the intestinal wall were found after 42 days. Compared to the group fed with Ventar D, the broilers of the control group showed a performance decrease of 11.8 % with an 8% lower final fattening weight and a 3 points poorer FCR.

Necrotic enteristis lesion scores

Based on the results of the above studies, the ROI for Ventar D due to the improvement in feed efficiency by 3 and 5 points could be 1:3.5 and 1:6.5, respectively. Similarly, the net returns for using Ventar D could be 0.007 and 0.013 € / kg live weight, given the 3 and 5 points improvements in feed efficiency. The ROI for Ventar D use could be even higher thanks to additional benefits such as improvements in litter condition and foot pad lesions, reduced veterinary cost, etc., depending on the prevailing challenges.

The future of feeding is here

The first study results for Ventar D underscore that, if combined and delivered right, phytomolecules can transform broiler performance from inside the gut. Ventar D’s stable delivery system ensures a constant amount of active molecules in targeted intestinal sites and, therefore, supports a favorable intestinal flora. With Ventar D supplementation, subclinical intestinal infections due to C. perfringens or other enteric bacteria can be very well kept in check, ensuring improved broiler productivity and production profitability.



Skinner, James T., Sharon Bauer, Virginia Young, Gail Pauling, and Jeff Wilson. “An Economic Analysis of the Impact of Subclinical (Mild) Necrotic Enteritis in Broiler Chickens.” Avian Diseases 54, no. 4 (December 1, 2010): 1237–40.

Tandoğan, M., and H. Çiçek. “Technical Performance and Cost Analysis of Broiler Production in Turkey.” Revista Brasileira de Ciência Avícola 18, no. 1 (2016): 169–74.

Zhai, Hengxiao, Hong Liu, Shikui Wang, Jinlong Wu, and Anna-Maria Kluenter. “Potential of Essential Oils for Poultry and Pigs.” Animal Nutrition 4, no. 2 (June 2018): 179–86.

Reducing apo-esters: What are the alternatives?

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By Dr. Twan van Gerwe, Global Technical Director, EW Nutrition

A year ago, the European Commission announced regulation (EU) 2020/1400 – restricting the use of ethyl ester of β-apo-8’-carotenoic acid (generally known as ‘apo-ester’). Starting on 26 October 2021, this legislation restricts the use of apo-ester in poultry feed to 5 mg/kg for laying hens and 15 mg/kg for broilers.  

As apo-esters is a synthetic pigment – not naturally occurring in nature – this measure was taken because the authorities could not guarantee safety upon exposure to the user. Limiting the concentration in feed would reduce this risk to acceptable levels, according to the legislators’ decision.  

Why use apo-esters in the first place? 

Apo-ester is a synthetic yellow colorant, with good stability in premixtures and complete feed. It also has a high deposition rate in the yolk, making it an effective egg yolk colorant.  

Its ability to be applied through premix facilitates the proper dispersion in the final feed, which is relevant if micro-dosing systems are lacking in the feed mill. 

Why was the legislative change necessary? 

The legislative change which limits the use of synthetic apo-ester is based on the precautionary principle and in line with a broader market trend: away from synthetic (non-natural) components, towards the use of naturally occurring alternatives.  

The alternative to apo-ester

Natural yellow pigments, typically based on lutein and zeaxanthin produced from marigold oleoresin, are available in the market and can be used to reach the egg yolk pigmentation desired by the consumer. In contrast to apo-ester, these natural solutions are functional antioxidants, further contributing to the egg’s nutritious composition. 

Challenges for natural alternatives 

However, stability in premixtures and complete feed can be a challenge, with inconsistent yolk coloration as a risk. Safety can also be an issue, so it is important to ask for Quality Control measures routinely applied to avoid contamination with undesired substances (e.g., dioxins). To limit the risk of producing eggs with insufficient yolk coloration, it is important to select natural pigments with excellent stability and deposition efficiency. 

What is the best natural alternative to apo-ester? 

EW Nutrition’s natural pigment Colortek® Yellow B, produced with a proprietary technology, withstands the harsh conditions in premixtures, while the unique saponification process provides unparalleled deposition rates.  

Moreover, Colortek® Yellow B is the most concentrated natural pigment on the market, making it the perfect premix-delivered colorant in the egg industry. If you want to produce all-natural eggs without worrying about the stability of the product or the reliability of your egg coloration, please contact your local EW Nutrition person. 


Encapsulation: How a modern phytogenic feed additive makes all the difference

feed quality pellets kv yellow

By Technical Team, EW Nutrition


Secondary plant extracts have been shown to improve digestion, have positive effects on intestinal health, and offer protection against oxidative stress in various scientific studies in recent years. Their use as a feed additive has become established and various mixtures, adapted to the various objectives, are widely available.

However, their use in pelleted feed has been criticized for some time.  In particular, an unsatisfactory reproducibility of the positive influences on performance parameters is the focus of criticism. The causes invoked for the loss of quantifiable benefits are inadequately standardized raw materials, as well as uncontrollable and uneven losses of the valuable phytomolecules contained during compound feed production.

modern phytogenic feed additive makes all the difference

Delivery mechanisms influence product benefits

The animal production industry has long attempted to reduce its need for antibiotic drugs to an indispensable minimum. As a result, more natural and nature-identical feed additives have been used for preventive health maintenance. These categories include numerous substances that are known in human nutrition in the field of aromatic plants and herbs, or in traditional medicine as medicinal herbs.

The first available products of these phytogenic additives were simply added to compound feed. The desired parts of the plant were, like spices and herbs in human nutrition, crushed or ground into the premix. Alternatively, liquid plant extracts were placed on a suitable carrier (e.g. diatomaceous earth) beforehand in order to then incorporate them into the premix. These procedures are usually less than precise and may be responsible for the difficult reproducibility of positive results mentioned at the beginning.

Another negative factor that should not be underestimated is the varying concentration and composition of the active substances in the plant. This composition is essentially dependent on the site conditions, such as weather, soil, community and harvest time [Ehrlinger, 2007]. In an oil obtained from thyme, the content of the relevant phenol thymol can therefore vary between 30% and 70% [Lindner, 1987]. These extreme fluctuations are avoided with modern phytogenic additives through the use of nature-identical ingredients.

Effective encapsulation is key to stability

The loss of valuable phytomolecules under discussion can also be traced back to the natural origin of the raw materials. Some phytomolecules (e.g. cineole) are volatile even at low temperatures. In regular medicinal use, this effect is mainly employed with cold products. Thus essential oils, such as of mint and eucalyptus, can be added to hot water and inhaled via the resultant steam.

In the process of pelleting in compound feed production, temperatures between 60°C and 90°C are common, depending on the type of production. The process can last for several minutes until the cooling process is over. Sensitive additives can be easily inactivated or volatilized during this step.

A technical solution for the preservation of temperature-sensitive additives is using a protective cover. This is, for instance, an already established practice for enzymes. Such so-called encapsulation is already used successfully in high-quality products with phytogenic additives. The volatile substances should be protected by a coating with fat or starch so that the majority (>70%) of the ingredients can also be found after pelleting.

Unfortunately, complete protection is not possible with this capsule, as this simple protective cover can be broken open by mechanical pressure during grinding and pelletizing. New types of microencapsulation further reduce losses. In a sponge-like type of microencapsulation, if a capsule is destroyed, only a small proportion of the chambers filled with volatile phytomolecules are damaged.

High protection and recovery with Ventar D

A new type of encapsulation, developed by EW Nutrition for use in feed, delivers further optimization. Results show that the technology implemented in Ventar D ensures very high recovery rates of the sensitive phytomolecules even under demanding pelleting conditions.

In a comparative study with encapsulated products established on the market, Ventar D was able to achieve the highest recovery rates in all three tested scenarios (70°C, 45 sec; 80°C, 90 sec; 90°C, 180 sec). In the stress test at a temperature of 90°C for 180 seconds, at least 84% of the valuable phytomolecules were recovered, while the comparison products varied between 70% and 82%. A constant recovery rate of 90% was achieved for Ventar D under simpler conditions.

Phytomolecule recovery rates under processing conditions, relative to mash baseline (100%)

Phytomolecule recovery rates under processing conditions, relative to mash baseline (100%)

Site-specific release of active ingredients

The major gastrointestinal pathogens (like Clostridia spp., Salmonella spp., E. coli, etc.) are present across the gastrointestinal tract after the proventriculus. This leads to infection or lesions at different sites of preference, reaching up to ceca. Any feed-based solution should have a profound antimicrobial effect. It is, however, also crucial that active ingredients are released across the gastrointestinal tract, for a better contribution to intestinal health.

The unique, innovative delivery system used for Ventar D specifically addresses this point, which many traditional coating technologies do not.  Other encapsulation technologies tend to release the active ingredient either too early or too late (depending on the coating composition). The active ingredients in Ventar D reach across sites in the gastrointestinal tract and exert antimicrobial effects, supporting optimal gut health and improving performance.

Economically and ecologically sustainable

In the past, the losses mentioned in compound feed production and especially in pelleting were described as largely unavoidable. To obtain the desired effect of the valuable phytomolecules in the finished product, higher use of products was recommended and thus increased costs to the end-users and the associated CO2 footprint, lowering sustainability overall.

The modern encapsulation technology used in Ventar D now offers significantly better protection for the valuable phytomolecules and, in addition to the economic advantage, also offers more efficient use of the resources required for production.


Hashemi, S. R .; Davoodi, H .; 2011; Herbal plants and their derivatives as growth and health promoters in animal nutrition; Vet Res Commun (2011) 35: 169-180; DOI 10.1007 / s11259-010-9458-2; Springer Science + Business Media BV, 2011

Ehrlinger, M., 2007: Phytogenic additives in animal nutrition. Inaugural dissertation. Munich: Veterinary Faculty of the Ludwig Maximilians University in Munich.

Lindner, U., 1987: Aromatic plants – cultivation and use. Contribution to the special show – Medicinal and Spice Plants (Federal Garden Show 1987), Teaching and Research Institute for Horticulture Auweiler-Friesdorf, Düsseldorf.