Conference Report
By M. Rosenthal, Global Application Manager Swine, EW Nutrition GmbH

Sustainability is essential for the long-term survival of our planet. In pig production, sustainability involves maintaining economically viable outputs while simultaneously safeguarding animal health and welfare and minimizing environmental impact. The goal is to produce pork that is profitable, ethical, and has a minimal ecological footprint.

Phytomolecules, the bioactive constituents of plant-derived essential oils, play a promising role in advancing this goal. With multifunctional gut health benefits including antimicrobial, anti-inflammatory, antioxidant, and digestive-supportive properties, phytomolecules help maintain gut health and reduce the need for antibiotics. By improving feed efficiency, enhancing resilience, and supporting intestinal integrity, phytomolecules contribute to both sustainability and efficiency in pig production systems.

Targeting sustainability in pig production

Achieving sustainability in pig production requires a balanced approach that considers three key perspectives: those of the producer, the pig, and the environment.
For the producer, sustainable pig production must be profitable to ensure the long-term viability of the industry. This includes factors such as efficient feed conversion, optimized production practices, and fair market prices.

Another aspect is the maintenance of animal health and well-being, which is essential for optimal pig performance and can be achieved by providing appropriate housing, nutrition, and veterinary care, as well as minimizing stress and disease.

From an environmental perspective, minimizing negative impacts, such as greenhouse gas emissions, water pollution, and land degradation, is a key objective. Various strategies, such as improved manure management, efficient nutrient utilization, reuse of farm resources like manure and water, and the use of by-products from other industries as feed ingredients, can be applied.

Strategy for efficient pig production

Historically, pig production has relied heavily on the use of antibiotics to control enteric pathogens, promote gut health, and enhance growth. While effective in the short term, this practice led to unintended consequences, including the emergence of antimicrobial resistance (amr), disruption of microbiota across multiple organ systems, difficulties in manure management, and environmental contamination.

These outcomes triggered societal concern, regulatory interventions, and economic pressure, prompting a shift away from routine antibiotic use. The industry now faces increasing expectations for environmentally responsible practices, reduced dependence on antibiotics, and cost-effective, sustainable solutions.
Achieving both efficiency and sustainability in pig production requires a holistic, system-wide approach that includes an innovative, solution-oriented mindset, optimized management practices, and the adoption of effective gut health antibiotic alternatives.

The foundation of efficiency the gut

The pigs gastrointestinal tract is the largest and most vulnerable interface between the pig and its external environment. It is a highly organized ecosystem comprised of epithelial cells, the mucosal immune system, and a diverse microbiome consisting of both beneficial commensal microbes and potentially harmful pathogens.
The functions of the gut include nutrient absorption, chemosensing of nutrients and other compounds, immune defence, and balancing the highly diverse microbiome within this complex environment (Furness et al. , 2013). Disruption of this ecosystems homeostasis can impair not only gut function and health but also negatively affect the overall well-being and growth efficiency of the pig.

When evaluating antibiotic alternatives to support this ecosystems homeostasis in the face of challenges, considerations include safety for humans, animals, and the environment, cost-effectiveness, antimicrobial efficacy, the ability to increase nutrient availability, and to modulate immune activation and inflammation.

Functional feed additives commonly utilized in pig nutrition, alone or in combination, include organic acids, probiotics, immunoglobulins, medium-chain fatty acids, and phytomolecules.

Phytomolecules: supporting gut health and performance

Phytomolecules are the bioactive components of plant-derived essential oils. Due to the variability in phytomolecule content and the presence of volatile and astringent components in essential oil extracts, utilizing commercial phytomolecule products is recommended. Proprietary formulations utilize encapsulation or matrix technology to protect the phytomolecules from damage or loss during storage, processing, and passage through the stomach.

Extensive research in humans and animals has identified phytomolecules as having antimicrobial, anti-inflammatory, antioxidative, and coccidiostatic properties. They enhance digestibility and immunity, promote gut health through differential modulation of bacterial populations, and reduce inflammation and oxidative stress (Brenes et al., 2010; Puvaca et al. , 2013; Chitprasert et al., 2014). Phytomolecules most researched and utilized in pig feed additives to date include terpenes (e. G., carvacrol and thymol) and phenylpropenes (e.g., cinnamaldehyde and eugenol).

1. Direct antimicrobial activity of phytomolecules

Phytomolecules such as carvacrol and thymol provide broad-spectrum antimicrobial activities against Gram- and Gram+ bacteria, fungi, and yeast and are regarded as promising alternatives to antibiotics in swine production systems (Lambert et al., 2001; Delaquis et al., 2002; Abbaszadeh et al., 2014).

Phytomolecules directly target bacterial cells through multiple mechanisms, with the cell wall and membrane being major sites of action. The lipophilic structure of phytomolecules enables their entry through bacterial membranes among the fatty acid chains, causing the cell wall and membranes to expand and become more fluid. This damage collapses the cell wall and cytoplasmic membrane, resulting in the destruction of membrane proteins, the coagulation of the cytoplasm, and a reduction in proton motive force. The result is leakage of vital intracellular contents and death of the bacterial cell (Cox et al., 1998; Faleiro, 2011; Nazzaro et al., 2013; Yap et al., 2014). For example, thymol and carvacrol can damage the outer membrane of Salmonella typhimurium and Escherichia coli o157: h7 (Helander et al., 1998).

A further direct antimicrobial action involves phytomolecules acting as trans-membrane carriers, exchanging a hydroxyl proton for a potassium ion, resulting in dissipation of the ph gradient and electrical potential over the bacterial cytoplasmic membrane. The result is a reduced proton motive force and the depletion of the intracellular adenosine triphosphate (APT) pools. Loss of potassium further inhibits bacterial function as it is needed for the activation of cytoplasmic enzymes to maintain osmotic pressure and regulate intracellular pH. (Wendakoon et al., 1995).

In summary, the primary direct antimicrobial mechanism of action for terpene and phenylpropene phytomolecules is related to their effects on cell walls and cytoplasmic membranes, and energy metabolism of pathogenic bacteria.

2. Indirect antimicrobial activity of phytomolecules

Phytomolecules indirectly impact the physiological functioning and virulence capability of pathogenic bacteria through the interference of quorum-sensing (QS). QS involves pathogenic bacteria producing signaling molecules that are released based on cell numbers. The detection of these molecules regulates pathogen population behavior such as attachment, biofilm formation, and motility, i. e. , virulence (Greenberg, 2003; Joshi et al., 2016).

QS mechanisms require signal synthesis, signal accumulation, and signal detection, providing three opportunities for QS inhibitors to disrupt pathogenic bacteria from causing disease (Czajkowski and Jafra, 2009; Lasarre and Federle, 2013). Eugenol and carvacrol have been extensively studied for their QS inhibition activities (Zhou et al., 2013; Burt et al., 2014).

3. Combinations increase efficacy

Additional antimicrobial effects can be seen when different phytomolecules are combined, and/or applied with other functional additives such as organic acids (Souza et al., 2009; Hulankova and Borilova, 2011). Zhou et al. (2007) reported that carvacrol or thymol in combination with acetic or citric acid had a better efficacy against S. typhimurium when compared to the individual phytomolecule or organic acid. In recent studies, results have shown in vivo efficacy of such synergistic dietary strategies in pigs (Diao et al., 2015; Balasubramanian et al., 2016). The combined inclusion of phytomolecules and organic acids in pig diets before slaughter may hinder Salmonella shedding and seroprevalence (Walia et al., 2017; Noirrit et al., 2016).

4. Phytomolecules are more than antimicrobials

In addition to acting as antimicrobials, phytomolecules enhance production efficiency through multiple complementary mechanisms, including direct anti-inflammatory, antioxidative, digestive, and gut barrier-supportive effects.

Anti-inflammatory effects: Gut inflammation in pigs not only compromises intestinal function and barrier integrity but also has a direct negative impact on growth performance and overall health. Chronic or excessive immune activation diverts energy away from productive processes such as growth and feed efficiency.

Phytomolecules have demonstrated the ability to modulate immune responses by influencing key cell-signalling pathways involved in inflammation. For example, compounds such as cinnamaldehyde and carvacrol can modulate the activity of critical transcription factors, including nuclear factor erythroid 2 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB). Through this dual action, phytomolecules can simultaneously activate antioxidant defences and suppress pro-inflammatory signalling, thereby reducing intestinal inflammation and supporting improved performance outcomes (Krois-mayr et al., 2008; Wondrak et al., 2010; Zou et al., 2016).

Antioxidant effects: oxidative stress is a major biological challenge in modern swine production systems, where high-performance animals are frequently exposed to stressors such as weaning, disease challenges, heat stress, mycotoxin exposure, transport, and overcrowding. These stressors promote the generation of reactive oxygen species (ROS), and when ROS production exceeds the capacity of the pig’s antioxidant defence systems, oxidative stress occurs.

This imbalance can negatively affect growth, immunity, muscle integrity, feed intake, milk yield, and reproductive performance, including increased abortion rates in gestating sows (Zhou et al., 2013; Burt et al., 2014). As a result, there is growing interest in the use of natural antioxidant compounds, particularly phytomolecules, to counteract these detrimental effects. For example, carvacrol and thymol (1:1 ratio) at 100 mg/kg dietary supplementation reduced weaning-associated oxidative stress by decreasing TNF-α mRNA expression in the intestinal mucosa (Wei et al., 2017).

Additionally, carvacrol supplementation in the diets of late gestation and lactating sows under oxidative stress conditions significantly improved piglet performance (Tan et al., 2015).

Digestive function: The gastrointestinal tract functions not only as a site for nutrient absorption but also as a sensory organ. Specialized chemosensors in the gut monitor the concentration and composition of nutrients, playing a crucial role in the regulation of digestive enzyme secretion, gut peptide release, feed intake, and nutrient absorption and metabolism.

Studies in weaner piglets have shown that certain phytomolecules can stimulate the secretion of digestive enzymes and enhance gastrointestinal function (Maenner et al., 2011; Li et al., 2012).

Tight junctions and gut barrier integrity: The intestinal epithelium functions as a highly dynamic and selective barrier, facilitating the absorption of fluids and solutes while preventing the translocation of pathogens and toxins into underlying tissues. This barrier function occurs through intercellular tight junctions. During episodes of mucosal inflammation, the integrity of these junctions can be compromised, leading to increased intestinal permeability, reduced nutrient absorption, and systemic immune activation and inflammation.

Research has shown that phytomolecules can enhance transepithelial electrical resistance and upregulate the expression of tight junction proteins, reducing epithelial permeability and maintaining a functional barrier, even under inflammatory conditions (Yu et al., 2020; Kim and Kim, 2019).

Sustainable efficiency in pig production supported by in-feed phytomolecules

As the pig industry moves away from reliance on in-feed antibiotics, the need for sustainable, efficient, and health-focused production strategies has never been greater. Modern pig production systems must respond to societal expectations, regulatory mandates, and environmental pressures, while still maintaining profitability and high animal welfare standards.

Central to this transformation is a holistic approach-one that includes a shift in mindset among stakeholders, optimized management across all production domains, and the strategic use of effective antibiotic alternatives. The gastrointestinal tract, as the core of nutrient absorption and immune defence, is a critical control point for supporting health and performance.

Phytomolecules and other functional feed additives have demonstrated potential to enhance gut integrity, reduce inflammation, combat oxidative stress, and improve nutrient utilization. While no single solution can fully replace antibiotics, targeted combinations of these compounds have shown the most consistent success in promoting gut health and sustainable performance.

With continued innovation, collaboration, and science-based application of these alternatives, the industry is well-positioned to achieve its goals of profitable, ethical, and ecologically responsible pork production for the future.

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By Dr. Inge Heinzl, Editor EW Nutrition

Gut health is a critical factor in poultry production, influencing growth performance, feed efficiency, and overall bird health. A well-functioning digestive system ensures optimal nutrient absorption and ultimately contributes to economic sustainability in poultry farming.

However, another essential function of the gut is its significant role in immune defense, as evidenced by the fact that 80% of all active immune cells are in the gut. It is essential for the organism to keep a sensitive balance by eliminating invading pathogens while maintaining self-tolerance to avoid autoimmunity. Being 1.5 to 2.3 m long and with a big contact area to the external environment, the gut is the first line of defense when pathogens have orally entered the organism. For this purpose, the intestine has several specialized cells and a plethora of diverse microorganisms – the microbiome.

A balanced gut environment, therefore, enhances resistance to diseases, helps prevent infections, and reduces the need for antibiotics.

Which tools are available in the gut to counteract pathogenic attacks?

The gut wall, per se, has several fixed tools to fight pathogenic offenses, such as the mucus layers and the epithelium with highly specialized cells. Figure 1 shows in detail the different parts of the gut immune system.

1. Mucus layers

The mucus layers form the first host-derived line of defense. They help trap invasive bacteria and facilitate their removal via luminal flow. The protective properties may depend on whether the mucin is neutral or acidic, sialylated or sulfated (Broom and Kogut, 2018). The glycoprotein mucins forming the mucus layer (mainly MUC2 in the small and large intestine and MUC5ac in the proventriculus) are produced by the goblet cells, part of the intestinal epithelium just beneath.

2. Intestinal epithelium

The one-layered intestinal epithelium represents a physical barrier and consists of normal enterocytes, as well as specialized cells. All the cells are closely linked by tight junctions, consisting of claudin, occludin, and junctional adhesion molecules (JAM).
The following diverse specialized cells protect the organism from pathogenic attacks:

2.1 Proliferating stem cells

These cells are ready to replace damaged epithelial cells in the case of inflammation.

2.2 Paneth cells

Paneth cells are situated at the bottom of the Lieberkühn crypts, neighboring the stem cells in the jejunum and the ileum. Paneth cells have different tasks:
In normal conditions, they maintain homeostasis by regulating the microbiome’s composition via the secretion of antimicrobial peptides, which are accumulated in apically oriented secretory granules, performing phagocytosis and efferocytosis. Additionally, the Paneth cells provide niche factors for the intestinal stem cell compartment, absorb heavy metals, and preserve the integrity of the intestinal barrier. If one or more of these functions are impaired, intestinal and systemic inflammations or infections can develop (Wallaeys et al., 2022). The number of Paneth cells and their diameter can be enhanced via feeding. Agarwal et al. (2022) noticed a significant increase in the number and diameter of Paneth cells after feeding quinoa soluble fiber and/or quercetin 3-glucoside.

2.3 M cells

M cells (M coming from microfold and indicating the structure) are specialized epithelial cells localized along the antimesenteric border in the epithelium of the ileum. They are crucial for the immune system and an essential part of the gut-associated lymphoid tissue (GALT), a sub-system of the mucosa-associated lymphoid tissue (MALT).
M cells play an important role in the function of the immune system. They act as a transport system for antigens. They sample antigens (macromolecules, bacteria, viruses, small parasites) via the apical membrane. After the phagocytosis of the foreign organism/substance, the antigen gets through the cell and is consigned to cells of the adaptive immune system (e.g., the B-cells) at the basal side. The exact transport and the handover to the cells of the adaptive immune system are still unclear. It is also not clarified whether the antigens are processed inside the cells.

2.4 Dendritic cells

Dendritic cells are a kind of leucocyte derived from the bone marrow. Immature dendritic cells have a star-like shape. They are specialized to identify, uptake, transport, process, and present antigens to other immune system cells on their surface. To identify and uptake harmful substances/microbes, they carry receptors on their surface that recognize the attributes often occurring in pathogenic viruses, bacteria, and fungi. After contact with the antigen, the cell moves to secondary lymphoid tissue, and in the intestine, this is predominantly Mucosa-Associated Lymphoid Tissue (MALT). Arriving as mature and not phagocytizing dendritic cells, they present the antigens of the pathogens to the T-lymphocytes. For this purpose, they use cell surface proteins (MHC proteins). This presentation, together with co-stimulators and cytokines, activates naïve T-lymphocytes to develop into the relevant T-cell (fighting viruses, bacteria…) and proliferate, leading to the clearance of the pathogen.
On the other hand, dendritic cells can also suppress an immune reaction if the “suspicious subjects” are harmless or belong to the organism. Dendritic cells are the most potent antigen-presenting cells of the immune system.

2.5 Goblet cells

Goblet cells originate from pluripotent stem cells and are located between the enterocytes in the inner mucus layer of the intestine. Goblet cells develop and mature rapidly after hatching due to external stimuli such as environmental and dietary factors, but also intestinal microbiota (Duangnumsawang et al., 2021). They derive their name from their goblet-like appearance. The basal site is thin, but the cell gets thicker toward the apical side. In the thicker cell organisms, vesicles with mucins are stored and explosively released to the surface by exocytosis.

The mucins (MUC2) are viscous, slime-forming substances consisting of a protein string bound to many sugar chains. Due to their oligosaccharide chain structure, they offer adhesion binding sites for intestinal commensal bacteria and enhance probiotic colonization (Liu et al, 2020). They have a high water-binding capacity, which is responsible for their slimy and protective characteristics. In the case of inflammation, mucin production can increase strongly.

By providing bicarbonate for proper mucin unfolding in the small intestine, goblet cells help maintain homeostasis and the intestinal barrier function. Furthermore, goblet cells can form goblet cell-associated passages (GAPs) and deliver luminal substances to the antigen-presenting cells in the underlying lamina propria that can start an adaptive immune response (Knoop and Newberry, 2018).
As with Paneth cells, the number of goblet cells also increases by feeding quinoa soluble fibers.

2.6 Neuroendocrine cells

Enterochromaffin cells are neuroendocrine cells found in the epithelium of the whole digestive tract, mainly in the small intestine, the colon, and the ceca. They belong to the enteric endocrine system, are part of the diffuse neuroendocrine system, and produce 95% of the serotonin in the organism. Enterochromaffin cells act as chemo- and mechanosensors. They react to free fatty acids, amino acids, and other chemicals as well as physical forces occurring during peristaltic activity in the gut, thus modulating the secretion of water and electrolytes as well as gut motility and visceral sensation of pain (Linan-Rico et al., 2016; Diwakarla et al., 2018).

Serotonin, on its side, has been shown to affect the composition of the gut microbiota (Kwon et al., 2019) and to modulate bacterial physiology (Knecht et al., 2016). Gut-derived serotonin is responsible for immune responses (Baganz and Blakely, 2012) but also for the regulation of other functions such as bone development (Chabbi-Achengli et al., 2012), gut motility, and platelet aggregation (Berger et al., 2009). A deficient serotonergic system can cause psychopathological behaviors such as feather pecking.

3. Last but not least – the microbiome

The poultry gut microbiome consists of bacteria, fungi, protozoa, and viruses. Beneficial microbes, such as Lactobacillus, Bifidobacterium, and Bacteroides, contribute to gut health and immunity. 

On the one hand, microbes are involved in digestion and nutrient synthesis. They assist in breaking down fiber, producing short-chain fatty acids, and synthesizing essential vitamins. On the other hand, they contribute to immune defense:

Beneficial bacteria (BB) prevent the colonization of harmful microbes:
The bacteria inhabiting the poultry gut act against pathogens by competing with them for nutrients and binding sites at the intestinal mucosa.

Beneficial bacteria prevent/reduce inflammation and stabilize the intestinal mucosa
Abaidullah et al. (2019) showed in their review how beneficial bacteria influence the immune response to diverse viruses (AIV, IBDV, MDV, NDV).
Bacteria such as Collinsella, Faecalibacterium, Oscillibacter, etc., increase the release of IFN-α, IFN-β, and IL-22. These substances control virus replication and repair mucosal tissue damage. Other bacteria, such as Clostridium XIVa or Firmicutes, provoke T-cells to produce anti-inflammatory cytokines to suppress inflammation. By promoting the antimicrobial peptides such as MUC, TFF, ZO, and tight junction proteins comprised of claudins, occludin, and zona occludens mRNA expression, Bacteroides, Candidatus, SMB53, Parabacteroides, Lactobacillus, Paenibacillus, Enterococcus, and Streptococcus spp. inhibit pathobiont colonization and translocation, and suppress inflammation. Butyrate succinate and lactate, produced by Faecalibacterium and Blautia spp., provide energy and reduce inflammation.
Bacteroides fragilis produce bacterial polysaccharides that communicate with the immune system and influence the transformation of CD4+ (T-helper cells) and Foxp3+ cells (the master transcription factor of regulatory T cells in mammals, but also present in chicken (Burkhardt et al., 2022)). 

“Negative” bacteria increase inflammation and enhance viral shedding
Clostridium Cluster XI, Salmonella, and Shigella downregulate the anti-inflammatory and tight junction-stabilizing substances, which would be increased by the beneficial bacteria and increase IFN-γ and IF-17A to cause mucosal inflammation and tissue damage, as well as increased virus replication and fecal shedding. Further bacteria, which enhance mucosal and GIT inflammation, are Desulfovibrionaceae, producing hydrogen sulfides, Vampirovibrio, Clostridium cluster XIVb, and the genus Rumicoccus. They induce the pro-inflammatory cytokines IL-6 and IL-1β. The latter three bacteria also increase viral shedding. Salmonella typhimurium and Campylobacter jejuni also achieve higher viral shedding by decreasing viral-specific IgG and IgA production (Abaidullah et al., 2019)

Factors impairing intestinal immune defense

As the previous paragraph indicates, an imbalance of the intestinal microbiome called dysbiosis makes chickens more prone to diseases such as necrotic enteritis (Stanley et al., 2014). Several factors are disturbing the balance in the microbiome (Heinzl,  2020):

• An abrupt change of feed
• High contents of non-starch polysaccharides increase viscosity, decrease passage rate, lower the digestibility of other nutrients, and serve as nutrients for, e.g., Clostridium perfringens
• High protein levels can also serve as a substrate for pathogens and cause a shift in the balance of the intestinal flora
• Finely ground feed does not stimulate the gizzard muscles to do their work. pH increases, transit time decreases, and pathogenic microbes such as Salmonella, Campylobacter, and Clostridia proliferate.
• Stress (heat or cold stress, re-assembling of groups, high stocking densities)
• Mycotoxins

However, besides all these factors causing an overgrowth of commensal bacteria such as E. coli, ingested pathogens such as Marek’s or Newcastle Disease viruses can also cause this imbalance.

Immune defense in the gut – an interplay of different tools that must be protected

The first line of defense, the intestine, comprises different tools working together to fight pathogens and harmful substances. Besides the mucus layers and the specialized cells, the intestinal microbiome plays an essential role in immune defense by competing with pathogens for nutrients and binding sites, enhancing the secretion of anti-inflammatory substances, and stimulating the production of interferons, which fight the pathogens. However, several factors can impact the balance of the microbiome and cause dysbiosis. The best protection of this sensitive equilibrium can support the organism in defending against diseases and maintaining immunity and performance. Understanding the interplay between microbiota, immune function, and nutrition allows for effective strategies to enhance poultry health while reducing reliance on antibiotics. Future research will continue to provide insights into optimizing gut-immune interactions in poultry production.

References

Abaidullah, Muhammad, Shuwei Peng, Muhammad Kamran, Xu Song, and Zhongqiong Yin. “Current Findings on Gut Microbiota Mediated Immune Modulation against Viral Diseases in Chicken.” Viruses 11, no. 8 (July 25, 2019): 681. https://doi.org/10.3390/v11080681. 

Baganz, Nicole L., and Randy D. Blakely. “A Dialogue between the Immune System and Brain, Spoken in the Language of Serotonin.” ACS Chemical Neuroscience 4, no. 1 (December 24, 2012): 48–63. https://doi.org/10.1021/cn300186b. 

Berger, Miles, John A. Gray, and Bryan L. Roth. “The Expanded Biology of Serotonin.” Annual Review of Medicine 60, no. 1 (February 1, 2009): 355–66. https://doi.org/10.1146/annurev.med.60.042307.110802. 

Broom, Leon J., and Michael H. Kogut. “The Role of the Gut Microbiome in Shaping the Immune System of Chickens.” Veterinary Immunology and Immunopathology 204 (October 2018): 44–51. https://doi.org/10.1016/j.vetimm.2018.10.002. 

Burkhardt, Nina B, Daniel Elleder, Benjamin Schusser, Veronika Krchlíková, Thomas W Göbel, Sonja Härtle, and Bernd Kaspers. “The Discovery of Chicken Foxp3 Demands Redefinition of Avian Regulatory T Cells.” The Journal of Immunology 208, no. 5 (March 1, 2022): 1128–38. https://doi.org/10.4049/jimmunol.2000301. 

Chabbi-Achengli, Yasmine, Amélie E. Coudert, Jacques Callebert, Valérie Geoffroy, Francine Côté, Corinne Collet, and Marie-Christine de Vernejoul. “Decreased Osteoclastogenesis in Serotonin-Deficient Mice.” Proceedings of the National Academy of Sciences 109, no. 7 (January 30, 2012): 2567–72. https://doi.org/10.1073/pnas.1117792109. 

Clarke, G, S Grenham, P Scully, P Fitzgerald, R D Moloney, F Shanahan, T G Dinan, and J F Cryan. “The Microbiome-Gut-Brain Axis during Early Life Regulates the Hippocampal Serotonergic System in a Sex-Dependent Manner.” Molecular Psychiatry 18, no. 6 (June 2013): 666–73. https://doi.org/10.1038/mp.2012.77. 

Diwakarla, S., L. J. Fothergill, J. Fakhry, B. Callaghan, and J. B. Furness. “Heterogeneity of Enterochromaffin Cells within the Gastrointestinal Tract.” Neurogastroenterology & Motility 29, no. 6 (May 9, 2017). https://doi.org/10.1111/nmo.13101. 

Duangnumsawang, Yada, Jürgen Zentek, and Farshad Goodarzi Boroojeni. “Development and Functional Properties of Intestinal Mucus Layer in Poultry.” Frontiers in Immunology 12 (October 4, 2021). https://doi.org/10.3389/fimmu.2021.745849. 

Heinzl, Inge. “Necrotic Enteritis: The Complete Overview.” EW Nutrition, August 8, 2023. https://ew-nutrition.com/necrotic-enteritis-complete-overview/. 

Knecht, Leslie D., Gregory O’Connor, Rahul Mittal, Xue Z. Liu, Pirouz Daftarian, Sapna K. Deo, and Sylvia Daunert. “Serotonin Activates Bacterial Quorum Sensing and Enhances the Virulence of Pseudomonas Aeruginosa in the Host.” EBioMedicine 9 (July 2016): 161–69. https://doi.org/10.1016/j.ebiom.2016.05.037. 

Kong, Shanshan, Yanhui H. Zhang, and Weiqiang Zhang. “Regulation of Intestinal Epithelial Cells Properties and Functions by Amino Acids.” BioMed Research International 2018 (2018): 1–10. https://doi.org/10.1155/2018/2819154. 

Kwon, Yun Han, Huaqing Wang, Emmanuel Denou, Jean-Eric Ghia, Laura Rossi, Michelle E. Fontes, Steve P. Bernier, et al. “Modulation of Gut Microbiota Composition by Serotonin Signaling Influences Intestinal Immune Response and Susceptibility to Colitis.” Cellular and Molecular Gastroenterology and Hepatology 7, no. 4 (2019): 709–28. https://doi.org/10.1016/j.jcmgh.2019.01.004. 

Linan-Rico, Andromeda, Fernando Ochoa-Cortes, Arthur Beyder, Suren Soghomonyan, Alix Zuleta-Alarcon, Vincenzo Coppola, and Fievos L. Christofi. “Mechanosensory Signaling in Enterochromaffin Cells and 5-HT Release: Potential Implications for Gut Inflammation.” Frontiers in Neuroscience 10 (December 19, 2016). https://doi.org/10.3389/fnins.2016.00564. 

Liu, Yang, Xinjie Yu, Jianxin Zhao, Hao Zhang, Qixiao Zhai, and Wei Chen. “The Role of MUC2 Mucin in Intestinal Homeostasis and the Impact of Dietary Components on MUC2 Expression.” International Journal of Biological Macromolecules 164 (December 2020): 884–91. https://doi.org/10.1016/j.ijbiomac.2020.07.191. 

Lyte, Mark. “Microbial Endocrinology in the Microbiome-Gut-Brain Axis: How Bacterial Production and Utilization of Neurochemicals Influence Behavior.” PLoS Pathogens 9, no. 11 (November 14, 2013). https://doi.org/10.1371/journal.ppat.1003726. 

Marcobal, A., P. C. Kashyap, T. A. Nelson, P. A. Aronov, M. S. Donia, A. Spormann, M. A. Fischbach, and J. L. Sonnenburg. “A Metabolomic View of How the Human Gut Microbiota Impacts the Host Metabolome Using Humanized and Gnotobiotic Mice.” The ISME Journal 7, no. 10 (June 6, 2013): 1933–43. https://doi.org/10.1038/ismej.2013.89. 

Stanley, Dragana, Shu-Biao Wu, Nicholas Rodgers, Robert A. Swick, and Robert J. Moore. “Differential Responses of Cecal Microbiota to Fishmeal, Eimeria and Clostridium Perfringens in a Necrotic Enteritis Challenge Model in Chickens.” PLoS ONE 9, no. 8 (August 28, 2014). https://doi.org/10.1371/journal.pone.0104739. 

Wallaeys, Charlotte, Natalia Garcia‐Gonzalez, and Claude Libert. “Paneth Cells as the Cornerstones of Intestinal and Organismal Health: A Primer.” EMBO Molecular Medicine 15, no. 2 (December 27, 2022). https://doi.org/10.15252/emmm.202216427. 

Yano, Jessica M., Kristie Yu, Gregory P. Donaldson, Gauri G. Shastri, Phoebe Ann, Liang Ma, Cathryn R. Nagler, Rustem F. Ismagilov, Sarkis K. Mazmanian, and Elaine Y. Hsiao. “Indigenous Bacteria from the Gut Microbiota Regulate Host Serotonin Biosynthesis.” Cell 163, no. 1 (September 2015): 258. https://doi.org/10.1016/j.cell.2015.09.017.

Recently, The Poultry Site’s Sarah Mikesell interviewed Predrag Persak, EW Nutrition’s Regional Technical Manager for Northern Europe. The conversation covered topics as wide as sustainability and challenges in poultry production, and as narrow as intestinal permeability. Thanks to The Poultry Site for the great talk!

Watch the video

Sarah Mikesell, The Poultry Site: Hi, this is Sarah Mikesell with The Poultry Site, and today we are here with Predrag Peršak. He is the Regional Technical Manager for Northern Europe with EW Nutrition. Thanks for being with us today, Predrag.

Predrag Peršak, EW Nutrition: Nice to be here, Sarah. Thank you for inviting me.

SM: Very good. It’s nice to visit with you. And today, Predrag and I are in Berlin, Germany, at an exclusive event for the poultry industry called Producing for the Future, which is sponsored by EW Nutrition. You are one of our speakers today, Predrag, so I’m going to ask you just a few questions to let everybody know a little bit about your presentation.

You’ve described animal nutrition as “never boring and never finished.” What makes this field so dynamic and constantly evolving for you?

PP: I’ve been in animal nutrition for about 25 years. And in those 25 years, I would say that not even half a year passed without something extraordinary happening. From genetics to animal husbandry, especially here in Europe, we also have a lot of pressure from consumers and slaughterhouses to adapt production to the needs of the customers.

Sustainability, sourcing raw materials, and the variety of raw materials available in Europe – and the constant development of new ones – make life for an animal nutritionist very, very interesting. It’s also very challenging, and through these challenges you learn a lot.

So, applying what we learned 20 years ago is simply not enough anymore. For someone who wants to be challenged every day with new things, this is definitely the right industry to be in – especially now.

SM: Excellent. Can you explain your holistic approach to animal nutrition and how considering multiple factors benefits practical applications on farms?

PP: The concept of a holistic approach in animal nutrition is not new. But for me – being both a veterinarian and a nutritionist – it means having deeper insight into the animal itself, into all the metabolic processes, and also into the external influences: husbandry, genetics, diseases, and management. Looking at how all of these interact, we can only really solve problems by looking at the animal as a whole system.

The same applies to feed production. You cannot look at a feed mill as just one compartment. You have to look at sourcing raw materials, their quality, how they are processed – milling, pelleting, and other technologies – and then see how that feed performs on the farm.

So, a holistic approach can be applied both from the animal perspective and from the feed production perspective, across all steps and processes. This is something we use and promote daily in our work with customers.

SM: Very good. You’ve worked with unconventional protein and fiber sources. We’re hearing a lot more about that recently. What are those, and what potential do they bring to animal nutrition?

PP: When I talk about unconventional protein and fiber sources, we need to remember that the global feed production scene is very diverse. What applies in the U.S. or Brazil does not necessarily apply in Europe or the Far East.

Here in Europe, we try to use not by-products but co-products of food production. For example, different fractions of rapeseed or sunflower meal, which are widely produced in Europe but not often used by mainstream nutritionists due to certain limitations. By finding the right processing methods and combining them with technologies, we can make these unconventional materials usable in mainstream nutrition.

The same goes for fiber sources. Both fermentable and structural fibers are increasingly important for intestinal and digestive development, as well as for overall animal health. So, processing fibers in ways that maximize usability while minimizing negative effects is a big part of my work.

SM: From a cost standpoint for producers, are those lower-cost inputs, or just alternatives they need to look at?

PP: In Germany we have a perfect expression for this: “yes and no.” There is always pressure on price, especially in poultry, because food must be accessible to everyone. But at the same time, food must not harm the environment or human health, and we should use all resources not fit for humans but still usable for animals.

So, it’s not only about cost – about availability and sustainability. Working with just two, three, or five raw materials for a long time is not the way forward. The way forward is to think of everything that can be used properly, for the benefit of the animals, and ultimately to produce enough food for the world.

Also, using locally available products is important. Feed production is very diverse around the world—raw materials in Southeast Asia differ completely from those in Europe, Brazil, or the U.S. Using technologies to enable the use of locally produced by-products makes production not only sustainable, but also economically viable for local communities. That’s really the core of the feed industry: using what is produced locally.

SM: Interesting. Very cool. How does your interdisciplinary work across poultry, pigs, and ruminants give you unique insights that might be missed with a narrower focus?

PP: I come from a small feed mill in a small country, Croatia. There, you don’t have deep specialization by species or even by category, as you find in larger markets. Specialization has its advantages, but it can also limit creativity and “outside-the-box” thinking.

By working with ruminants, I learned about fermentation processes – knowledge that can be applied to pigs and even to poultry. For example, fermentation can reduce anti-nutritional factors, allowing higher inclusion levels of certain raw materials in poultry diets.

With pigs, fermentation of fibers – especially in piglets – is crucial, and some of that knowledge could be applied to turkeys, where we still face health issues.

So, working across species demands a lot – it leaves little time for other things – but it opens up unique perspectives and cross-species applications that benefit the entire livestock industry.

SM: I was talking with someone yesterday about mycotoxins – there’s a lot of research in pigs but less in poultry. That’s kind of what you’re talking about, right? Applying knowledge across species?

PP: Absolutely. We’re focused now on poultry, but we can learn from poultry too – not only about feeding but also about farm management, biosecurity, and more. These lessons can also apply to pigs or ruminants.

It’s all holistic – you cannot solve everything with nutrition alone. It’s always a package.

SM: You presented today about the importance of intestinal permeability. Why is it important, and how can understanding it impact animal health and performance outcomes?

PP: Intestinal permeability is one of the key features we use to describe gut health. Personally, I’m very practical. For 20 years we’ve talked about “gut health,” but the real question for veterinarians and nutritionists is: what do we actually do with that knowledge?

In my presentation, I explained intestinal permeability as a “point of no return” in gut health. When leaky gut develops, everything else can deteriorate – faster or slower – but it won’t return to normal without intervention.

By comparing how different stressors or pathogens impact intestinal permeability, we can better understand severity and decide where to focus. Nutritionists already pay attention to thousands of factors, but we need to identify the most impactful ones. That was my key message: focus on the most important drivers.

SM: And leaky gut has really become something the whole industry is talking about, right? I’ve even seen it in human health – my doctor has posters about it.

PP: Exactly. Across cows, pigs, and poultry, leaky gut is getting a lot of attention. It’s a physiological or pathophysiological feature that marks the point of no return.

We can talk about dysbiosis and all the causes, but once you reach leaky gut, you understand where intervention is needed. And it’s not just hype. For example, recently Nature published research showing certain types of human bone marrow conditions are linked to leaky gut and microbial influence on blood processes.

So, this is not a passing trend. It’s fundamental. And once we solve one issue, another door opens. That’s why this industry is never boring.

SM: Very good. Well, thank you for all the information today, Predrag.

PP: Thank you, Sarah. It was a pleasure to talk with you.

Watch the video on The Poultry Site.

By Dr. Inge Heinzl, Editor EW Nutrition and
Marie Gallissot, Global Manager Feed Quality Solutions EW Nutrition

Antibiotic resistance is a growing global health concern, making infections more complicated to treat and increasing the risk of disease spread, severe illness, and death. While overuse and misuse of antibiotics are the primary causes, recent research has uncovered another unexpected contributor: mycotoxins. Among these, deoxynivalenol (DON), a toxin commonly found in contaminated grains, has been shown to significantly alter gut microbiota and promote antibiotic resistance. This article examines how DON impacts gut bacteria, influences antibiotic resistance, and highlights why this issue warrants urgent attention.

Mycotoxins – originators of antimicrobial resistance?

Actually, it would be logical…

Alexander Fleming discovered Penicillin when he returned after the summer holidays and saw that a mold had grown on the agar plate he had prepared. Around the mold, Staphylococcus was unable to proliferate. The reason was a substance produced by the mold – penicillin, which, like other toxins produced by molds, is a mycotoxin. In his article about the origin of antibiotics and mycotoxins, Shier (2011) stated that antibiotics and mycotoxins share considerable similarities in structure, metabolic roles, and biosynthesis.

A short excursus to antimicrobial resistance

In general, the primary mechanisms of resistance involve the prevention or limitation of the antimicrobial substance’s uptake, modifying the drug target, inactivating the drug, or facilitating its discharge with efflux pumps.

There are two types of resistance: natural resistance, which is further divided into intrinsic and induced resistance, and acquired resistance.

Intrinsic resistance is a “characteristic” of a bacterial species and is not dependent on antibiotic exposure. An example is the reduced permeability of the outer membrane of gram-negative bacteria, which prevents certain antibiotics from entering.

Induced resistance, however, needs to be initiated by antibiotics. Here, multidrug-efflux pumps can be mentioned.

The third one, acquired resistance, refers to the process by which bacteria acquire genetic material, the resistance genes, from other bacteria that are resistant. The mechanisms include vertical transfer to daughter cells and horizontal transfer, such as the transfer from dead bacteria to living ones, by viruses, or the transfer of plasmids (Reygaert, 2018).

Deoxynivalenol (DON) promotes resistance in gut microbiota

A Chinese group of researchers (Deng et al., 2025) examined for the first time the influence of DON on the intestinal microbiota of chickens. One of the most alarming findings is DON’s ability to enhance antibiotic resistance. It contributes to this issue in several ways:

1. Encouraging resistant bacteria – By disrupting microbial balance, DON provides a survival advantage to bacteria that carry resistance genes.
2. Activating resistance genes – Studies suggest that DON can increase the expression of genes that help bacteria withstand antibiotics.
3. Enhancing gene transfer – Bacteria can share resistance genes through horizontal gene transfer. DON appears to promote this process, making antibiotic-resistant strains spread more rapidly.
4. Weakening antibiotic effectiveness – DON-induced changes in the gut environment can reduce the effectiveness of antibiotics, making treatments less successful.

A further indication that mycotoxins can enhance resistance is the significant overlap in the geographical distribution of antimicrobial-resistant bacteria and genes with that of mycotoxins, as noted by Deng et al.

Which protection mechanisms do bacteria have against mycotoxins?

In the case of mycotoxins, bacteria employ similar molecular mechanisms to those used against antibiotics. In an in vitro experiment, Hassan et al. (2019) challenged Devosia mutans, a gram-negative bacterium, with DON in the growth medium. DON inhibits protein synthesis, induces oxidative stress, and compromises cell membrane integrity in eucaryotic cells. Hassan et al. asserted three adaptive mechanisms as the response to the challenge:

1. Activation of cellular membrane proteins (adenosine 5’-triphosphate-binding cassette -ABC- transporters) responsible for the unidirectional transport of substrates, either outward or inward. These ABC transporters can work as drug efflux pumps.
2. Production of DON-specific deactivation enzymes, thereby engaging a toxin-specific pyrroloquinoline quinone-dependent detoxification pathway. This enables the bacterial isolate to transform DON to a non-toxic stereoisomer.
3. Upregulation of auxiliary coping proteins, such as porins (transmembrane proteins involved in metabolite exchange), glutathione S-transferases, and phosphotransferases, both of which are likely involved in the detoxification of xenobiotics.

Public health implications and preventive measures

Given the widespread presence of DON in food and animal feed, its potential role in antibiotic resistance poses a serious threat. The combination of increased bacterial resistance and weakened antibiotic efficacy could lead to more difficult-to-treat infections. This is particularly concerning in hospital settings, where antibiotic-resistant infections already cause high mortality rates.

To address the issue, several strategies can be implemented:

1. Reducing DON contamination: Implementing improved agricultural practices, such as crop rotation, the use of fungal-resistant crop varieties, and maintaining proper storage conditions, can help limit fungal growth and DON production.
2. Monitoring food and feed supply – Strict regulations and testing for DON contamination in grains and animal feed are essential to minimize human and animal exposure.
3. Effective mycotoxin risk management at feed mill and farm levels: Using tools such as MasterRisk and effective products combatting mycotoxins.
4. Maintaining gut health: A healthy diet rich in fiber, probiotics, and gut health-supporting feed supplements, such as Ventar D or products from the Activo line, may help counteract some of the adverse effects of DON on gut microbiota.
5. Developing new treatments: Research into alternative therapies and new antibiotics is crucial to combat the rise of antibiotic resistance.

Antimicrobial resistance: Be aware of the mycotoxins!

The connection between mycotoxins, such as DON, and antibiotic resistance underscores the need for a broader perspective on public health and food safety and once again brings the “One Health Concept” into focus. While antibiotic overuse remains the primary driver of resistance, environmental factors, such as exposure to mycotoxins, should not be overlooked. By increasing awareness, enhancing food safety regulations, and investing in research, we can take steps to mitigate this emerging threat and safeguard the effectiveness of antibiotics for future generations.

References:

Deng, Fengru, Chuying Yao, Linyu Ke, Meichan Chen, Mi Huang, Jikai Wen, Qingmei Chen, Jun Jiang, and Yiqun Deng. “Emerging Threat to Antibiotic Resistance: Impact of Mycotoxin Deoxynivalenol on Gut Microbiota and Clonal Expansion of Extensively Drug-Resistant Enterococci.” Environment International 197 (March 2025): 109353.
https://doi.org/10.1016/j.envint.2025.109353.

Hassan, Yousef I., Jian Wei He, Dion Lepp, and Ting Zhou. “Understanding the Bacterial Response to Mycotoxins: The Transcriptomic Analysis of Deoxynivalenol-Induced Changes in Devosia Mutans 17-2-E-8.” Frontiers in Pharmacology 10 (November 14, 2019).
https://doi.org/10.3389/fphar.2019.01098.

Reygaert, Wanda C. “An Overview of the Antimicrobial Resistance Mechanisms of Bacteria.” AIMS Microbiology 4, no. 3 (2018): 482–501.
https://doi.org/10.3934/microbiol.2018.3.482.

Shier, W. Thomas. “On the Origin of Antibiotics and Mycotoxins.” Toxin Reviews 30, no. 1 (January 28, 2011): 6–30.
https://doi.org/10.3109/15569543.2011.550862.

Smith, William P., Benjamin R. Wucher, Carey D. Nadell, and Kevin R. Foster. “Bacterial Defences: Mechanisms, Evolution and Antimicrobial Resistance.” Nature Reviews Microbiology 21, no. 8 (April 24, 2023): 519–34.
https://doi.org/10.1038/s41579-023-00877-3.

by Ajay Bhoyar, Global Technical Manager, EW Nutrition

Anyone working with today’s fast-growing broiler chicken knows that it is a sensitive creature – and so is its gut health. Thanks to continuous improvements in terms of genetics and breeding, nutrition and feeding, as well as general management strategies, broiler production has tremendously upped performance and efficiency over the past decades. It is estimated that, between 1957 and 2005, the broiler growth rate increased by over 400%, while the feed conversion ratio dropped by 50%.

These impressive improvements, however, have come at the cost of intense pressure on the birds’ digestive system, which needs to process large quantities of feed in little time. To achieve optimal growth, a broiler’s gastrointestinal tract (GIT) needs to be in perfect health, all the time. Unsurprisingly, enteric diseases such as necrotic enteritis, which severely damages the intestinal mucosa, hamper the intestines’ capacity to absorb nutrients and induce an inflammatory immune response.

The modern broiler’s gut – a high-performing, but sensitive system

However, in a system as high performing as the modern broiler’s GIT, much less can lead to problems. From when they are day-old chicks up to slaughter, broilers go through several challenging phases during which they are more likely to show impaired gut functionality, e.g. after vaccinations or feed changes. Good management practices go a long way towards eliminating unnecessary stressors for the animals, but some challenging periods are unavoidable.

The transition from starter to grower diets is a classic situation when nutrients are very likely to not be well digested and build up in the gut, fueling the proliferation of harmful microbes. Immunosuppressive stress in combination with an immature intestinal microflora results in disturbances to the bacterial microbiota. At “best”, this entails temporarily reduce nutrient absorption, in the worst case the birds will suffer serious intestinal diseases.

Phytomolecules – the intelligent alternative to antibiotics

To safeguard performance during stressful periods, poultry producers need to anticipate them and proactively provide effective gut health support. For many years, this support came in the form of antibiotic growth promoters (AGP): administered prophylactically, they were effective at keeping harmful enteric bacteria in check. However, due to grave concerns about the development of antimicrobial resistance, non-therapeutic antibiotics use has been banned in many countries. Alternatives need to focus on improving feed digestibility and strengthening gut health, attacking the root causes of why the intestinal microflora would become unbalanced in the first place.

Phytomolecules are secondary metabolites active in the defense mechanisms of plants. Studies have found that certain phytomolecules stimulate digestive enzyme activities and stabilize the gut microflora, “leading to improved feed utilization and less exposure to growth-depressing disorders associated with digestion and metabolism” (Zhai et al., 2018). With other trials showing positive effects on broilers’ growth performance and feed conversion, the research indicates that phytomolecules might also specifically support chickens during challenging phases.

The effect of phytomolecules on broilers during a challenging phase

A study was conducted over a period of 49 days on a commercial broiler farm of an AGP-free integration operation in Japan. The farm reported gut health challenges in the second and third week of the fattening period due to vaccinations and changes to the animals’ diets. The trial included 15504 Ross 308 broilers, divided into two groups. The negative control group included a total of 7242 birds, kept in another house.

All the birds were fed the standard feed of the farm. The trial group (8262 birds) received Activo Liquid, which contains a synergistic combination of phytomolecules, administered directly through the drinking water. Activo Liquid was given at an inclusion rate of 200ml per 1000L of water (3.3 US fl oz per gallon of stock solution, diluted at 1:128), from day 8 until day 25, for 8 hours a day.

The results are summarized in Figure 1:

Figure 1: Improved broiler performance for Activo Liquid group (day 49)

The Activo Liquid group clearly showed performance improvements compared to the control group. Livability augmented by 1.5%, while the feed conversion rate improved by 3.2%. This resulted in a more than 5% higher score in terms of the performance index.

Challenging times? Tackle them using phytomolecules

Poultry producers take great care to eliminate unnecessary sources of stress for their birds. Nonetheless, during their lifecycle, broiler chickens face challenging periods during which the balance of the intestinal microflora can easily become disturbed, with consequences ranging from decreased nutrient absorption to full-blown enteric disease.

The trial reviewed here showed that, after receiving Activo Liquid, broilers raised without AGPs showed encouraging performance improvements during a challenging phase of feed changes and vaccinations. Likely thanks to the activation of digestive enzymes and a stabilization of the gut flora, the broilers showed improved livability and feed conversion, thus delivering a much more robust performance during a critical phase of their lives. In times where the non-therapeutic use of antibiotics is no longer an option, phytomolecules allow poultry farmers to effectively support their animals during challenging times.

References

Photo Source: Aviagen

Adedokun, Sunday A., and Opeyemi C. Olojede. “Optimizing Gastrointestinal Integrity in Poultry: The Role of Nutrients and Feed Additives.” Frontiers in Veterinary Science 5 (January 31, 2019): 348.

Jamroz, D., T. Wertelecki, M. Houszka, and C. Kamel. “Influence of Diet Type on the Inclusion of Plant Origin Active Substances on Morphological and Histochemical Characteristics of the Stomach and Jejunum Walls in Chicken.” Journal of Animal Physiology and Animal Nutrition 90, no. 5-6 (March 23, 2006): 255–68. 

Tavárez, Marcos A., and Fausto Solis De Los Santos. “Impact of Genetics and Breeding on Broiler Production Performance: a Look into the Past, Present, and Future of the Industry.” Animal Frontiers 6, no. 4 (October 1, 2016): 37–41.

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.

Zuidhof, M. J., B. L. Schneider, V. L. Carney, D. R. Korver, and F. E. Robinson. “Growth, Efficiency, and Yield of Commercial Broilers from 1957, 1978, and 20051.” Poultry Science 93, no. 12 (December 2014): 2970–82. 

Press Release

EW Nutrition awarded the 2019 “Outstanding Contribution Award” for reducing antibiotic resistance in the layer industry

On August 28-29, the BBS & Excellent Product Award Ceremony for Reducing Antibiotic Resistance for the Layer Industry was held in Guangzhou.

China’s Ministry of Agriculture and Rural Affairs reiterated that, starting from January 1, 2020, China’s livestock industry will face the challenge of reducing antibiotic resistance. For layer-breeding enterprises, food safety is the bottom line, and the production of safe eggs without drug residue is the most basic requirement.

The introduction of the new policy is also an opportunity for industrial upgrading. To further discuss the topic, the technical organization of Guangdong’s poultry industry invited well-known domestic and international experts and representatives of leading layer enterprises in China, totaling more than 500 people. On this occasion, EW Nutrition received the 2019 Outstanding Contribution Award for reducing antibiotic resistance in the layer industry.

Mr. Wang Deshu, EW Nutition’s Sales Director for China, was honored to receive this prestigious award, which reinforces EW Nutrition’s vision: mitigating the impact of AMR by providing comprehensive animal nutrition solutions. He took the opportunity to restate his eagerness to cooperate with the government in its endeavor to eliminate the use of AGPs by 31 December 2020.

EW Nutrition Sales Director Mr. Wang Deshu

EW Nutrition

EW Nutrition GmbH, an affiliate of EW Group, is a German-based company with offices and affiliates around the world, holding a strong science-based product portfolio in the field of innovative feed additives. EW Nutrition offers holistic solutions for antibiotic reduction, young animal nutrition, gut health management, toxin risk management and more, including a complex range of services in these areas.

Press contact
Caroline Gong (Marketing Manager, China, EW Nutrition)
Email:   caroline.gong@ew-nutrition.com
Phone:  +86 021 6042 8390

Antibiotic growth promoters (AGPs) have routinely been used in intensive poultry production for improving birds’ performance. However, in recent years, reducing the use of antibiotics in animal production has become a top priority, due to concerns about the development of antibiotic-resistant bacteria and mounting consumer pressure. Multiple countries have introduced bans or severe restrictions on the non-therapeutic use of antibiotics, including in the US, where the Food and Drug Administration has implemented measures to curb the use of antibiotics since 2017.

However, the removal of AGPs poses challenges for poultry performance, including reduced feed efficiency, decreased daily weight gain, as well as higher mortality. Moreover, the withdrawal of AGPs in feed is widely recognized as one of the predisposing factors for necrotic enteritis (NE). NE is one of the most common and economically important poultry diseases, with an estimated global impact of US$ 5 to 6 billion per year. As a result of withdrawing AGPs, the usage of therapeutic antibiotics to treat NE has increased. To break out of this vicious cycle and to secure the efficiency of poultry production, alternatives are needed that combat NE where it starts: in the gut.

Necrotic enteritis: a complex disease

NE is caused by pathogenic strains of Clostridium perfringens (CP): ubiquitous, gram-positive, spore-forming anaerobic bacteria. The spores of CP can be found in poultry litter, feces, soil, dust, and contaminated feed. Low levels of different CP strains are naturally present in the intestines of healthy birds, kept in check by a balanced microbiome. However, when gut health is compromised, pathogenic strains can proliferate at the expense of unproblematic strains, resulting in clinical or sub-clinical NE.

Animals suffering from the clinical form show symptoms such as general depression, reluctance to move, and diarrhea, with mortality rates of up to 50%. Infected birds suffer from degenerated mucosa lesions in the small intestines. Even in its “mild”, subclinical form, which often goes unnoticed, the damage to the animals’ intestinal mucosa can result in permanently reduced performance and consequent economic losses for the producer.

Certain predisposing factors have been found to enable the proliferation of pathogenic strains in the gastrointestinal tract. Diet is a key example: the composition of the gut flora is directly linked to feed composition. High inclusion rates of cereals (barley, rye, oats, and wheat) that contain high levels of non-starch polysaccharides (NSPs), high levels of indigestible protein, and inclusion of proteins of animal origin (e.g. fishmeal) have been shown to predispose birds to NE.

A range of diseases (e.g. chicken infectious anemia, Gumboro, and Marek’s disease), but also other factors that have immunosuppressive effects, such as heat or cold stress, mycotoxins, feed changes, or high stocking density, render birds more susceptible to intestinal infections. The single most prominent predisposing factor for the occurrence of NE is the mucosal damage caused by coccidiosis.

Gut health is key to combating necrotic enteritis

To control NE, a holistic approach to optimizing the intestinal health of poultry is needed. It should take into account not only parameters such as diet, hygiene, and stress, but should also make use of innovative tools.

Phytomolecules, also known as secondary plant compounds, are essentially plants’ defense mechanisms against pathogens such as moulds, yeasts, and bacteria. Studies have demonstrated the antimicrobial effects of certain phytomolecules, including against antibiotic-resistant pathogens. Phytomolecules have also been found to boost the production of digestive enzymes, to suppress pro-inflammatory prostaglandins and have antioxidant properties. These features make them a potent tool for optimizing gut health, potentially to the point of replacing AGPs.

Can phytomolecules mitigate the impact of necrotic enteritis?

To study the impact of phytomolecules on the performance of broilers challenged with a NE-causing CP strain, a trial was conducted at a US-based research facility. In this 42-day study, 1050 male day-old Cobb 500 broiler chicks were divided into 3 groups, with 7 replicates of 50 chicks each.

On the first day, all animals were vaccinated against coccidiosis through a live oocyst spray vaccination. The experimental diets met or exceeded the National Research Council requirements, and were fed as crumbles/pellets. On days 19, 20, and 21, all pens, except the negative control group, were challenged with a broth culture of C. perfringens. A field isolate of CP known to cause NE (originating from a commercial broiler operation) was utilized as the challenge organism. On day 21, three birds from each pen were selected, sacrificed, group weighed, and examined for the degree of present NE lesions.

The positive control group received no supplements. The trial group received a synergistic combination of two phytogenic products containing standardized amounts of selected, microencapsulated phytomolecules: an in-feed phytogenic premix (Activo, EW Nutrition GmbH) and a liquid complementary feed supplied via the drinking water (Activo Liquid, EW Nutrition GmbH). The products were given at inclusion rates corresponding to the manufacturer’s baseline antibiotic reduction program recommendations (Figure 1):

Figure 1: Trial design

The trial results indicate that the addition of phytomolecules helps to mitigate the impact of NE on broilers’ performance. The group receiving Activo and Activo Liquid showed a better feed conversion (Figure 2) compared to the positive control group (NE challenge, no supplement). Also, better lesion scores were noted for animals receiving phytomolecules (0.7 and 1) than for the positive control group (1.6).

The most significant effect was observed concerning mortality: the group receiving Activo and Activo Liquid showed a 50% lower mortality rate than the positive control group (Figure 3). These results clearly indicate that phytomolecules can play an important role in mitigating losses due to NE.

Figure 2: Adjusted FCR

Figure 3: Lesion scores and mortality

Tackling necrotic enteritis in a sustainable way

In an age of AGP-free poultry production, a concerted focus on fostering animals’ gut health is key to achieving optimal performance. This study strongly demonstrates that, thanks to their antimicrobial, digestive, anti-inflammatory and antioxidant properties, phytomolecules effectively support birds’ intestinal health when challenged with NE. The inclusion of Activo and Activo Liquid, two phytogenic products designed to synergistically support birds during critical periods, resulted in improved feed conversion, better lesion scores, and 50% lower mortality.

In combination with good dietary, hygiene, and management practices, phytomolecules are therefore a potent tool for reducing the use of antibiotics: including Activo and Activo Liquid in their animals’ diets allows poultry producers to reduce the incidence of NE, to mitigate its economic impact in case of outbreaks, and therefore to control NE in a sustainable way.

By by Ajay Bhoyar, Global Technical Manager, EW Nutrition

References

Antonissen, Gunther, Siska Croubels, Frank Pasmans, Richard Ducatelle, Venessa Eeckhaut, Mathias Devreese, Marc Verlinden, Freddy Haesebrouck, Mia Eeckhout, Sarah De Saeger, Birgit Antlinger, Barbara Novak, An Martel, and Filip Van Immerseel. “Fumonisins Affect the Intestinal Microbial Homeostasis in Broiler Chickens, Predisposing to Necrotic Enteritis.” Veterinary Research 46, no. 1 (September 23, 2015): Article 98. doi:10.1186/s13567-015-0234-8.

Moore, Robert J. “Necrotic Enteritis Predisposing Factors in Broiler Chickens.” Avian Pathology 45, no. 3 (May 31, 2016): 275-81. doi:10.1080/03079457.2016.1150587.

Tang, Karen L., Niamh P. Caffrey, Diego B. Nóbrega, Susan C. Cork, Paul E. Ronksley, Herman W. Barkema, Alicia J. Polachek, Heather Ganshorn, Nishan Sharma, James D. Kellner, and William A. Ghali. “Restricting the Use of Antibiotics in Food-producing Animals and Its Associations with Antibiotic Resistance in Food-producing Animals and Human Beings: A Systematic Review and Meta-analysis.” The Lancet Planetary Health 1, no. 8 (November 6, 2017): 316-27. doi:10.1016/s2542-5196(17)30141-9.

Van Immerseel, Filip, Julian I. Rood, Robert J. Moore, and Richard W. Titball. “Rethinking Our Understanding of the Pathogenesis of Necrotic Enteritis in Chickens.” Trends in Microbiology 17, no. 1 (2009): 32-36. doi:10.1016/j.tim.2008.09.005.

Wade, Ben, and Anthony Keyburn. “The True Cost of Necrotic Enteritis.” PoultryWorld. October 09, 2015. Accessed August 19, 2019.

 Source Photo: Aviagen

Antimicrobial resistance (AMR) is a major threat to global public health. It is largely caused by the overuse of antibiotics in human medicine and agriculture. In intensive poultry production most antibiotics are used as antimicrobial growth promoters and/or used as prophylactic and metaphylactic treatments to healthy animals. Reducing such antibiotic interventions is crucial to lowering the incidence of AMR. However, antibiotic reduction often results in undesirable performance losses. Hence alternative solutions are needed to boost poultry performance. Phytomolecules have antimicrobial, digestive, anti-inflammatory and antioxidant properties, which could make them key to closing the performance gap.

Poultry performance depends on intestinal health

Poultry performance is to a large extent a function of intestinal health. The intestines process nutrients, electrolytes and water, produce mucin, secrete immunoglobulins and create a barrier against antigens and pathogens.

In addition, it is an important component of the body’s immune defense system. The intestine has to identify pathogens and reject them, but also has to tolerate harmless and beneficial microorganisms. If the intestines do not function properly this can lead to food intolerance, dysbiosis, infections and diseases. All of these are detrimental to feed conversion and therefore also to animal performance.

Antibiotics reduce the number of microorganisms in the intestinal tract. From a performance point of view this has two benefits: first, the number of pathogens is reduced and therefore also the likelihood of diseases; second, bacteria are eliminated as competitors for the available nutrients. However, the overuse of antibiotics not only engenders AMR: antibiotics also eliminate probiotic bacteria, which negatively impacts the digestive tracts’ microflora.

Products to boost poultry performance may be added to their feed or water. They range from pre- and probiotics to medium chain fatty acids and organic acids to plant extracts or phytomolecules. Especially the latter have the potential to substantially reduce the use of antibiotics in poultry farming.

Phytomolecules are promising tools for antibiotic reduction

Plants produce phytomolecules to fend off pathogens such as moulds, yeasts and bacteria. Their antimicrobial effect is achieved through a variety of complex mechanisms. Terpenoids and phenols, for example, disturb or destroy the pathogens’ cell wall. Other phytomolecules inhibit their growth by influencing their genetic material. Studies on broilers show that certain phytomolecules reduce the adhesion of pathogens such as to the wall of the intestine. Carvacrol and thymol were found to be effective against different species of Salmonella and Clostridium perfringens.

There is even evidence that secondary plant compounds also possess antimicrobial characteristics against antibiotic resistant pathogens. In-vitro trials with cinnamon oil, for example, showed antimicrobial effects against methicillin resistant Staphylococcus aureus, as well as against multiresistant E. coli, Klebsiella pneumoniae and Candida albicans.

Importantly, there are no known cases to date of bacteria developing resistances to phytomolecules. Moreover, phytomolecules increase the production and activity of digestive enzymes, they suppress the metabolism of pro-inflammatory prostaglandins and they act as antioxidants. Their properties thus make them a promising alternative to the non-therapeutic use of antibiotics.

Study design and results

In order to evaluate the effect of phytomolecules on poultry performance, multiple feeding studies were conducted on broilers and laying hens. They were given a phytogenic premix (Activo, EW Nutrition GmbH) that contains standardized  amounts of selected phytomolecules.

To achieve thermal stability during the feed processing and a targeted release in the birds’ gastrointestinal tract, the product is microencapsulated. For each , the studies evaluated both the tolerance of the premix and the efficacy of different dosages.

Study I: Evaluation of the dose dependent efficacy and tolerance of Activo for broilers
Animals:             400 broilers; age: 1-35 days of age
Feed:                  Basal starter and grower diets
Treatments:
– No supplement (negative control)
– 100 mg of Activo /kg of feed
– 1.000 mg of Activo /kg of feed
– 10.000 mg of Activo /kg of feed
Parameters:       weight gain, feed intake, feed conversion ratio, health status, and blood parameters

Results: The trial group given the diet supplemented with 100 mg/kg Activo showed significant improvements in body weight gain during the starter period (+4%) compared to the control group. Additional significant improvements in feed conversion ratio (FCR) in the growing period (+4%) resulted in an overall improvement in FCR of 3%. At a 1.000 mg/kg supplementation, a significant improvement in FCR of 6% was observed over the entire feeding period. Hematological parameters were within the reference range of healthy birds when feeding up to 10,000 Activo/ kg of feed.

Study II: Evaluation of the dose depending efficacy and tolerance of Activo for laying hens

Animals:             200 hens; age: 20 to 43 weeks
Feed:                  basal diet for laying hens
Treatments:
– No supplement (negative control)
– 100 mg of Activo/ kg of feed
– 250 mg of Activo/ kg of feed
– 500 mg of Activo/ kg of feed
– 5.000 mg of Activo/ kg of feed
Parameters:      weight gain, feed intake, feed conversion ratio, health status, and blood parameters

Results: Inclusion levels from 100 mg/kg of Activo onwards improved laying performance, egg mass and egg weight and reduced FCR compared to the control group. Results recorded for hematological parameters were within the reference range of healthy birds when feeding up to 5.000 mg Activo/ kg of feed.

Study III: Evaluation of the dose-dependent effects of Activo for coccidiosis vaccinated broilers

Animals:             960 broiler chickens; age: 42 days
Feed:                  Standard starter and finisher feed
Treatments:
– No supplement (negative control)
– 50 g of Activo /US ton of feed
– 100 g of Activo /US ton of feed
– 150 g of Activo /US ton of feed
– 200 g of Activo /US ton of feed
– 250 g of Activo /US ton of feed
– Antibiotic growth promoter (AGP)(positive control)
Parameters:      weight gain, feed efficiency
Specific:           In order to represent field conditions, the birds were challenged with used, homogenized litter.

Results: A clear dose response for both body weight gain and feed efficiency was observed (see Figure 1): the more phytogenic premix given, the better the birds’ performance. The group with 200g of Activo /US ton of feed showed similar performance levels than the positive control group supplemented with AGP.

Figure 1: Dose-dependent effects of for coccidiosis vaccinated broilers

Study IV:  Evaluation of the dose-dependent effects of Activo for laying hens

Animals:           40 hens; age: week 20 to 43
Feed:                basal diet for laying hens
Treatments:
– No supplement (negative control)
– 100 mg of Activo/ kg of feed
– 250 mg of Activo/ kg of feed
– 500 mg of Activo/ kg of feed
– 5.000 mg of Activo/ kg of feed
Parameters:      weight gain, feed intake, egg production, feed conversion ratio, health status
Duration:         168 days of feeding period

Results: The laying hens showed a higher laying rate when fed with a higher concentration of phytomolecules (Figure 2). Similarly improved results were observed for the feed efficiency. The more phytogenic premix added to their diet the better feed efficiency (Figure 3).

Figure 2: Dose-dependent effects of Activo on laying rate in laying hens

Figure 3: Dose-dependent effects of Activo on feed efficiency in laying hens

In conclusion, all four studies indicate that the inclusion of phytomolecules in broilers’ and laying hens’ diet improves their performance. Increasing levels of a phytogenic premix (Activo) significantly increased the production parameters for both groups. These improvements might bring performance in antibiotic-free poultry production on par with previous performance figures achieved with antimicrobial growth promoters.

The studies also showed that microencapsulated phytogenic premixes are safe when used in dose ranges recommended by the suppliers. No negative effects on animal health could be observed even at a 100 fold / 50 fold of the recommended inclusion rate in diets for broiler or laying hens, respectively. Thanks to their positive influence on intestinal health, phytomolecules thus boost poultry performance in a safe and effective way.

By Technical Team, EW Nutrition

Literature

Alanis, Alfonso J. “Resistance to Antibiotics: Are We in the Post-Antibiotic Era?” Archives of Medical Research 36, no. 6 (October 08, 2005): 697-705. doi:10.1016/j.arcmed.2005.06.009.

Borda-Molina, Daniel, Jana Seifert, and Amélia Camarinha-Silva. “Current Perspectives of the Chicken Gastrointestinal Tract and Its Microbiome.” Computational and Structural Biotechnology Journal 16 (March 15, 2018): 131-39. doi:10.1016/j.csbj.2018.03.002.

Diaz-Sanchez, Sandra, Doris Dsouza, Debrabrata Biswas, and Irene Hanning. “Botanical Alternatives to Antibiotics for Use in Organic Poultry Production.” Poultry Science 94, no. 6 (June 2015): 1419-430. doi:10.3382/ps/pev014.

Du, Encun, Weiwei Wang, Liping Gan, Zhui Li, Shuangshuang Guo, and Yuming Guo. “Effects of Thymol and Carvacrol Supplementation on Intestinal Integrity and Immune Responses of Broiler Chickens Challenged with Clostridium Perfringens.” Journal of Animal Science and Biotechnology 7, no. 19 (March 22, 2016). doi:10.1186/s40104-016-0079-7.

Gao, Pengfei, Chen Ma, Zheng Sun, Lifeng Wang, Shi Huang, Xiaoquan Su, Jian Xu, and Heping Zhang. “Feed-additive Probiotics Accelerate Yet Antibiotics Delay Intestinal Microbiota Maturation in Broiler Chicken.” Microbiome 5, no. 1 (August 03, 2017). doi:10.1186/s40168-017-0315-1.

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 (February 04, 2009): 586-97. doi:10.3390/molecules14020586.

Manafi, Milad, Mahdi Hedayati, Saeed Khalaji, and Mohammad Kamely. “Assessment of a Natural, Non-antibiotic Blend on Performance, Blood Biochemistry, Intestinal Microflora, and Morphology of Broilers Challenged with Escherichia Coli.” Revista Brasileira De Zootecnia 45, no. 12 (December 2016): 745-54. doi:10.1590/s1806-92902016001200003.

Photo source: Aviagen

Increased profitability in poultry production: EW Nutrition presents new comprehensive programs for the American market at Midwest Poultry Federation (MPF)
To support customers with effective solutions in animal production, EW Nutrition introduces the programs for Antibiotic Reduction and Toxin Risk Management in poultry. These programs contribute to solving the problem of antibiotic resistance by minimizing the input of antibiotics. In addition to innovative products the programs include customized consultancy services in the fields of animal nutrition, management and biosecurity.

At MPF, EW Nutrition will present new programs to reduce antibiotic use in broiler, broiler breeder and turkeys. A program to manage the toxin risk in poultry will also be introduced. One part of the programs is innovative products supporting gut and liver health and mitigating the impact of myco- and bacterial toxins. The other part is formed by consultancy services tailored to the particular needs of the customers.

The goals of the poultry programs are:

• stabilization of performance throughout the whole cycle
• constant high numbers of high quality chicks
• a reduced variety between flocks
• improved weight gain and feed conversion.

MARK RICHARDS, President of EW Nutrition USA

“Keeping performance high by simultaneously reducing the use of antibiotics is a balance act in animal production. We are convinced that the reduction of antibiotic use is the best way to reduce antibiotic resistance. With our comprehensive programs we support integrators, farmers and animals in coping with challenges occurring in animal production while increasing customers’ profitability.”

 EW Nutrition:

The customer-oriented company focusses on solving critical issues in animal nutrition by offering holistic and tailored programs for antibiotic reduction, toxin risk management and young animal nutrition. For this purpose EW Nutrition introduced innovative products and services resulting from solid R&D and business development. A global network of local commercial and technical support by experts guarantees the closeness to the customer. The reliable family-owned company is situated in Germany and has own R&D, production and application facilities in different parts of  the world.

Press contacts
EW Nutrition USA:   Mark Richards, mr@ew-nutrition.com

Another tool to reduce the use of antibiotics is the use of immunoglobulins from eggs.
Trials showed that this product is effective to support a calf’s start in life and also to offer support when challenged by various forms of diarrhoea.

The main cause for calf losses during the first two weeks of life is diarrhea. In general diarrhoea is characterised by more liquid being secreted than that being resorbed. However, diarrhoea is not a disease, but actually only a symptom. Diarrhea has a protective function for the animal, because the higher liquid volume in the gut increases motility and pathogens and toxins are excreted faster. Diarrhoea can occur for several reasons. It can be caused by incorrect nutrition, but also by pathogens such as bacteria, viruses and protozoa.

Bacteria in the gut
E. coli belong to the normal gut flora of humans and animals and can be mainly found in the colon. Only a fraction of the serotypes causes diseases. The pathogenicity of E.coli is linked to virulence factors. Decisive virulence factors are for example the fimbria used for the attachment to the gut wall and the bacteria’s ability to produce toxins.

Salmonella in general plays a secondary role in calf diarrhea, however, salmonellosis in cattle is a notifiable disease. Disease due to Clostridia is amongst the most expensive one in cattle farming globally. In herbivores, clostridia are part of the normal gastro-intestinal flora, only a few types can cause serious disease. In calves, Clostridium perfringens occurs with the different types A, C, and D. Rotaviruses are the most common viral pathogens causing diarrhoea in calves and lambs. They are mainly found at the age of 5 to 14 days. Coronaviruses normally attack calves at the age of 5 to 21 days. Cryptosporidium parvum is a protozoa and presumed to be the most common pathogen causing diarrhoea (prevalence up to more than 60 %) in calves.

Undigested feed and incorrect use of antibiotics
Plant raw materials (mainly soy products) are partly used in milk replacers as protein sources. These products contain carbohydrates, that cannot be digested by calves which can lead to diarrhea. The transition from milk to milk replacer can also be a reason.

An early application of tetracyclines and neomycin to young calves can lead to a change in the villi, malabsorption and therefore to slight diarrhoea. Longer therapies using high dosages of antibiotics can also lead to a bacterial superinfection of the gut. The problem is that in a disease situation, antibiotics are often used incorrectly. The use of antibiotics only makes sense when there is a bacterial diarrhea and not due to viruses, protozoa or poor feed management. To keep the use of antibiotics as low as possible, alternatives need to be considered.

Egg powder to add immunoglobulins
In order to achieve optimal results in calf rearing two approaches are possible. Firstly, the prophylaxis approach. This is the method of choice as diarrhoea can mostly be prevented. Therefore, it is necessary to supply the calf with the best possible equipment. As antibodies are one crucial but limiting factor in the colostrum of the “modern” cow, this gap needs to be minimised.  A study conducted in Germany in 2015 demonstrated that more than 50% of the new-born calves had a deficiency of immunoglobulins in the blood. Only 41% of the calves showed an adequate concentration of antibodies in the blood (>10 mg IgG/ml blood serum). Immunoglobulins contained in hen eggs (IgY) can partly compensate for poor colostrum quality and serve as a care package for young animals. A trial was conducted with an egg powder product* on a dairy farm (800 cows) in Brandenburg, Germany. In total 39 new-born calves were observed until weaning (65^th day of life). Before birth, the calves were already divided into control and trial group according to the lactation number of their mother cow. All calves were fed the same and received four litres of colostrum with ≥ 50 mg IgG /ml on the first day of life.

Control (n=20):            no additional supplementation
Trial group (n=19):      day 1 – 5: 100 g of the egg powder product per animal per day mixed into the colostrum or milk.

It was shown that the calves in the trial group showed a significantly higher (13%) weaning weight (105.74 kg compared to 93.45 kg in the control group) and 18%  higher average daily gain (999 g compared to 848 g in the control group) (Figure 1 and Figure 2).

Support during acute diarrhea
When diarrhea occurs, the calf has to be treated. So the second approach is to find the best and quickest solution. It is not always necessary to use antibiotics, as they do not work against virus or protozoa. Egg antibodies can be an answer when combined with electrolytes as the following trial shows. On a dairy farm (550 cows) in Germany a feeding trial with a product based on egg powder and electrolytes** was conducted from December 2017 to May 2018. Two groups of calves were used. Before birth the animals were allocated into the two groups according to the calving plan and were examined from day one until weaning (77^th day of life). All calves suffering from diarrhea (38 in total, 17 in the control and 21 in the trial group) were treated as follows:

Control (n=17):            Application of electrolytes
Trial group (n=21):      50 g of the egg powder and electrolytes product twice daily, stirred into the milk replacer until diarrhea stopped.

If the diarrhea did not stop or even got worse, the animals were treated with antibiotics. It was shown that in the control group the antibiotic treatment necessary was nearly twice as long as needed in the trial group (Figure 3). This means also that nearly twice the amount of antibiotics were used. This leads to the conclusion that calves in the trial group had an improved health status compared to calves in the control group. A further result from the improved health status was an increase in performance in the trial group (Figure 4).

The average daily weight gain of the trial group was 20% higher than in the control (600 vs. 500 g per day) leading to a significantly higher weaning weight (87.8 kg) than in the control (80.7 kg).

By Dr. Inge Heinzl, Editor EW Nutrition
Published in Dairy Global (Online and Printed), 10/2018