THE REGIONAL STRUCTURES OF WORLD EGG PRODUCTION IN 2023
Feeders Gió: the originals without grill
Specifically developed for great poultry farms, thanks to the easiness in the regulation of the feed and to the absence of grill (that avoid chicks perching) have many advantages: they are easy to use and their cleaning is extremely easy and fast too, leading to an overall reduction in labour costs.
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EDITORIAL
➤ Marianna Caterino
The egg market continues to face challenges, as evidenced by data released by the European Commission. Bird flu, rising production costs, and growing demand from the industrial and HoReCa sectors have disrupted the industry's balance. In 2024, there were over 650 avian influenza outbreaks in Europe. In the same year, more than 170 million birds were culled in the United States due to the disease. This had an impact on availability and prices.
In 2025, European egg prices began to rise again, reaching an average of €283.60 per 100 kilograms for category A eggs in week 13. This represents a 22.6% increase compared to the same period in 2024 and a 47% increase compared to the five-year historical average. Consumers, despite being affected by price increases, continue to favour eggs from cage-free farms. In fact, today, 62% of laying hens in the EU are raised in alternative systems. Barn, free-range, and organic systems are becoming increasingly prevalent. But the challenges are not only health-related or economic. Upcoming regulatory changes – such as the transition to cage-free farming and in-ovo sexing – necessitate new investments throughout the supply chain. Some countries are considering postponing these measures in order to reduce costs. This has sparked controversy among consumers and associations. Clearly, achieving a balance between sustainability, animal welfare, and affordability will be a challenge for the industry in the coming years. Therefore, the year 2025 promises to be a decisive one. It will be a year in which the egg market must once again prove its extraordinary adaptability.
REPORTAGE
From gut microbiota to lighting: integrated approaches for sustainable poultry farming
FOCUS
Stepping into barn digitalization
MARKETING
The regional structures of world egg production in 2023
MANAGEMENT
Perch usage in laying hens
NUTRITION
Priming young birds for gut health and resilience
VETERINARY
Concurrent infection of Histomonas meleagridis and Eimeria meleagridis in a turkey flock
MARKET GUIDE
UPCOMING
PESTICIDES RESIDUES IN FOOD: WHAT’S THE SITUATION IN THE EU?
The risk from pesticide residues to human health remains low, in line with previous years, EFSA said in its latest annual report. EFSA analysed thousands of samples collected in 2023 from commonly consumed products.
The report analyses information on pesticide residues gathered from random and targeted monitoring programmes. EFSA also published an interactive tool that allows users to browse the data in charts and graphs.
Random sampling shows consistent results
EFSA analysed the results of 13,246 random samples taken by EU Member States, Norway and Iceland from 12 of the most consumed food products in the EU as part of the EUcoordinated control programme (EU MACP). The EU MACP programme samples the same commodities every three years to track trends. For 2023 these were carrots, cauliflowers, kiwi fruits (green, red and yellow), onions, oranges, pears, potatoes, dried beans, brown rice, rye, bovine liver and poultry fat.
From this subset of samples analysed under the EU MACP, 99% were found to be compliant with EU legislation. This finding is consistent with the results obtained in 2020 (99.1%), when the same selection of products was sampled. Of the 2023 samples, 70% were free of quantifiable levels of residues, while 28% contained one or more residues within legal limits. Maximum residue levels (MRLs) were exceeded in 2% of samples, of which 1% were noncompliant after taking into account the measurement uncertainty.
Targeted sampling with high compliance rate
EFSA’s annual report on pesticide residues also includes the results from the Multiannual National Control Programme (MANCP), which gathers data from targeted sampling, based on the level of risk.
These national control programmes provided 132,793 samples, 98% of which were compliant with EU legislation. Compliance rates for the MANCP in 2021 and 2022 were 97.5% and 97.8%, respectively. Of the 2023 samples, 58% did not contain quantifiable residues, while 38.3% contained residues within legal limits and 3.7% exceeded the MRL, of which 2% were non-compliant.
Dietary risk assessment
The results from the monitoring programmes are a valuable source of information for estimating dietary exposure of EU consumers to pesticide residues. EFSA carried out a dietary risk assessment as part of its analysis of the results. The assessment shows the probability that consumers will be exposed to a quantity of residues above a certain safety threshold. Based on its assessment, EFSA concludes that there is a low risk to consumer health from the estimated exposure to pesticide residues in the foods tested.
The report also makes recommendations to increase the efficiency of European control systems for pesticide residues. For example, EFSA advises Member States to further investigate and monitor pesticide and crop combinations leading to non-compliances, and to continue monitoring pesticide residues in samples imported from outside the EU with a wide analytical scope.
2023 SUSTAINABILITY REPORT:
AVIAGEN’S GLOBAL COMMITMENT IN ACTION
Aviagen® has released its 2023 Sustainability Report, highlighting the company’s ongoing global commitment to building a more sustainable future for the poultry industry, the environment, and the communities that depend on both.
For decades, Aviagen has been dedicated to Breeding Success Together – not only with our customers, but with the entire global poultry sector. By developing healthy, efficient and resilient birds, supporting responsible management and driving innovation, we aim to advance the industry while protecting the environment and improving lives in the communities we serve.
The 2023 report brings this commitment to life. It offers a practical, transparent look at Aviagen’s sustainability journey –from our long-term strategy of balanced breeding to the daily efforts of our teams around the world.
Breeding for a better future
At the core of Aviagen’s sustainability approach is balanced breeding: selecting birds for efficiency, health, and welfare to sustain consistent improvements over time. Our ongoing progress in feed efficiency reduces environmental impact –conserving resources, lowering emissions, and enabling a more sustainable global food supply.
A shared commitment
Animal welfare and sustainability go hand in hand. The 2023 report shows how these principles are woven into Aviagen’s values and reflected in every area of our operations.
Global reach, local touch
A key feature of this year’s report is a series of “Sustainability in Action” stories – real examples of how Aviagen teams are living our values through environmental initiatives, community engagement, and on-the-ground innovation. These stories highlight the power of collaboration and shared responsibility to create meaningful, lasting change.
“We are pleased to share this report, reaffirming our commitment to the planet and its people,” said Jan Henriksen, CEO of Aviagen. “Sustainability has long been at the heart of our work, and we’re focused on making decisions today that will not only benefit the poultry sector but generations to come. This report is a reflection of that ongoing journey.”
The interactive report includes links to inspiring stories, key goals and deeper insights into Aviagen’s sustainability efforts across the globe.
Explore the full 2023 Sustainability Report: https://indd.adobe.com/view/7814933c-7edb-4768bcfd-43526cd7721d
REACH NEW HEIGHTS WITH YOUR BUSINESS AT
VIETSTOCK EXPO & FORUM 2025
Vietstock 2025 is the premier B2B exhibition in Vietnam and Southeast Asia, dedicated to livestock production, animal feed, animal health, and meat processing. Taking place from October 8-10, 2025, at SECC in Ho Chi Minh City.
As Southeast Asia’s livestock sector evolves rapidly, Vietstock Expo & Forum stands out as the region’s leading annual B2B platform professionals for feed, livestock, animal health, and meat processing. Recognized as Vietnam’s leading international exhibition for the livestock industry, Vietstock is part of Informa Markets’ trusted ASEAN-wide livestock and aquaculture exhibition series, renowned for connecting innovators, key decision-makers, and solution providers across the value chain. Scheduled from October 8–10, 2025 at the Saigon Exhibition and Convention Center (SECC), Ho Chi Minh City, Vietstock Expo & Forum is more than just a showcase of products, it fosters valuable conversations, drives regional collaboration, and highlights transformative solutions for a sustainable future. With more than 300 exhibitors and 13,000 professionals from over 40 countries expected, Vietstock 2025 will cover 13,000 sqm of exhibition space, offering businesses unparalleled opportunities to connect, collaborate, and lead in a rapidly advancing industry landscape.
Unlock new opportunities, create valuable partnerships
Join 13,000+ qualified trade visitors, including farm owners, feed millers, meat processors, distributors, veterinarians, and governments from across Vietnam and over 40 countries and regions. Vietstock offers you faceto-face access to the decision-makers who matter most, enabling high-value interactions that shorten the
sales cycle and open doors to new partnerships. Mr. Phung Duc Tien, Deputy Minister, Ministry of Agriculture and Environment shared his thoughts on Vietstock: “Exhibitors have noted that each year after Vietstock, their equipment sales increase. Our livestock and aquaculture technologies are continually being innovated, which plays a key role in boosting the industry’s productivity, quality, and competitiveness”.
Showcase innovation in a high-impact environment
With over 13,000 sqm of exhibition space and 300+ exhibiting companies, Vietstock 2025 brings together the entire livestock industry under one roof. Whether you offer feed technology, breeding solutions, animal health products, farm automation systems, or meat processing equipment, this is where innovation gets noticed. The exhibition is designed for maximum exposure, giving your brand the spotlight it deserves.
• Livestock Roadshow held in key livestock provinces across Vietnam, increases opportunities for exhibitors to connect directly with potential customers in these vital markets.
• Match & Meet Program - The platform offers a professional business networking space where exhibitors and industry leaders can network quickly and privately, opening up the opportunity to reach the “final decision” right at the event.
Maximize ROI with quality leads and targeted connections
Exhibiting at Vietstock is a strategic investment in measurable business outcomes. Capture high-quality leads, engage with key decision-makers, and position your solutions directly in front of industry buyers who are actively seeking innovative technologies and sustainable solutions to enhance productivity within livestock production.
Boost your lead generation with LeadGrab - Lead Retrieval Application. This tool enables exhibitors to efficiently capture visitor information by simply scanning badges, turning every interaction into a valuable business connection. Seamlessly track and follow up on potential leads to maximize ROI and accelerate your sales pipeline post-event.
Stay ahead of livestock trends & industry insights
During the three days of Vietstock 2025, benefit from technical seminars, industry forums, and policy briefings delivered by top industry experts and associations. Gain valuable knowledge, sustainability trends, animal welfare, biosecurity, and feed innovation, that can sharpen business strategy and inspire product development.
• Conferences & Technical Seminars: An education hub for technical knowledge and market updates in the livestock industry, features engaging sessions led by industry thought leaders, covers a diverse range of topics, from market trends and regulatory updates to technological advancements and best practices
• Biosecurity Asia Forum: The forum will focus on orientations, methods, and implementation strategies for biosecurity, which is a core value for sustainable development in the livestock industry
• Eggcellent Theatre: Vietstock celebrates World Egg Day at Eggcellent Theatre every year with many exciting activities: product showcase, workshops, seminars, free Egg-Gift-Away.
Stand out in Southeast Asia’s thriving livestock market
Vietnam is one of Asia’s fastest-growing markets for livestock production and meat processing. By exhibiting at Vietstock 2025, you position your business at the center of Southeast Asia’s agribusiness transformation. Strengthen brand visibility, enhance credibility, and become a recognized name in a market where trust and long-term partnerships are key to success.
Adding to the prestige of the event, the Vietstock Awards –13th edition will once again be hosted by the Department of Livestock Production and Veterinary (Ministry of Agriculture and Environment) offer a unique opportunity to elevate your brand. These prestigious awards honour organizations that have made outstanding contributions to Vietnam’s livestock sector. A nomination or win amplifies your brand, reinforces your leadership, and strengthens regional credibility.
Start your journey to success at Vietstock Expo & Forum 2025
Vietstock 2025 is your gateway to unlocking new growth opportunities and building long-lasting partnerships in the heart of Southeast Asia’s rapidly advancing livestock industry. With thousands of industry leaders and decisionmakers converging under one roof, this is the place to highlight your innovations, expand your reach, and position your brand for success in a competitive market.
USPOULTRY, RESEARCHERS DEVELOP VACCINES FOR THE CONTROL OF CHICKEN SPOTTY LIVER DISEASE
USPOULTRY and the USPOULTRY Foundation announce the completion of a funded research project by researchers from Iowa State University that worked to develop and evaluate bacterin-based vaccines for the control of spotty liver disease in poultry. The research is part of the Association’s comprehensive research program encompassing all phases of poultry and egg production and processing.
Project 735 – Development of vaccines for the control of chicken spotty liver disease
(Dr. Orhan Sahin, Iowa State University, Department of Veterinary Diagnostics and Production Animal Medicine)
Spotty Liver Disease (SLD) manifests as acute infectious hepatitis and causes a significant drop in egg production and high mortality in layer chickens. Due to the great economic losses incurred by SLD, it has become an important concern for the egg industry. Recently, Campylobacter hepaticus was identified as the causative agent for chicken SLD and was confirmed to infect the liver via the fecal-oral route and subsequent systemic spread. However, the virulence mechanisms of C. hepaticus remain unknown and currently, no commercial vaccines are available for the prevention and control of SLD. In other animals, Campylobacter bacterins are protective against systemic infection. The main goal of this project was to develop and evaluate bacterin-based vaccines for the control of SLD in poultry. The study consisted of two specific objectives. The first objective was to evaluate the homologous protection of experimental bacterins against SLD.An experimental bacterin would be prepared using a specific C hepaticus strain and oil adjuvant. Then the bacterin was assessed for the efficacy of protection against SLD by the homologous
challenge. In addition, one-dose and two-dose immunization schemes would be compared by homologous challenge. The second objective consisted of evaluating heterologous protection of experimental bacterins against SLD. Genomic sequence analysis has shown that diverse C hepaticus strains are associated with SLD outbreaks in the U.S. To assess whether the bacterin can produce broad protection against the diverse C hepaticus population, the efficacy of the
bacterin would be assessed by heterologous challenges (with three phylogenetically different representative isolates from the strain utilized).
To accomplish the objectives, researchers first ascertained the optimal immunization/challenge model for the selection of bacterial strains (single vs. multiple), chickens (SPF layers vs. commercial layers) and times of vaccination and inoculation. After several immunization and challenge experiments with different variables evaluated, it was determined that a multi-strain bacterin vaccine and a multistrain inoculum given multiple times was the best model for this purpose. Accordingly, a three-strain bacterin emulsified with an oil-based commercial adjuvant was used to immunize specific pathogen free (SPF) birds once or twice (at 11- and 15-weeks of age, respectively), followed by an oral challenge with a cocktail of three C hepaticus strains for three times (once every other day) at 23 weeks of age. Half of the birds in each group were necropsied at two and three weeks, respectively, after the last challenge. Birds were examined for the presence of SLD lesions, and bile and liver tissues were collected for C hepaticus culture.
Results showed that none of the birds developed gross liver lesions. Importantly, even though almost all of the birds (14 of 15 total) in the control group were positive with C.
hepaticus in the liver, only three birds (out of 17 total) in the one-dose vaccine group and a single bird (out of 18 total) in the two-dose vaccine groups were C. hepaticus positive. Thus, the protection rates for the one-dose and two-dose regimens are 82% and 94%, respectively. In agreement with the protection efficiency, ELISA analysis of the serum samples revealed the development of high-level specific antibodies against C hepaticus in both vaccinated groups. These results indicated that vaccination with the three-strain bacterin induced a robust humoral immunity in SPF layers and protected birds from challenge with a mixture of three genetically diverse strains, even with a single-dose regimen. The findings also indicate that the challenge model induces profound liver infection in unimmunized birds, which provides an alternative but reliable method for assessing protective immunity. Given that commercial vaccines are currently unavailable for SLD, the short-term impact of the project is the evidence that a multi-strain bacterin can be further developed to confer broad protection against SLD caused by C. hepaticus, and its long-term impact would be the advancement of commercialized vaccines to control SLD, contributing to the enhanced productivity and sustainability of the layer industry.
Source: USPOULTRY Foundation
INAUGURAL STATE OF THE WORLD’S ANIMAL HEALTH REPORT FINDS SEVERAL ANIMAL DISEASES REACHING NEW AREAS
Infectious animal diseases are affecting new areas and species, undermining global food security, human health and biodiversity, according to the first State of the World’s Animal Health report.
The new annual assessment, published by the World Organisation for Animal Health (WOAH), provides the first comprehensive review of animal disease trends, risks and challenges, from the uptake and availability of vaccines to the use of antibiotics in animals. Released ahead of WOAH’s 92nd General Session and its Animal Health Forum – where leading experts will gather to discuss vaccination and innovation in disease prevention – the report sets the stage for high-level discussions on how science-based vaccination strategies and emerging technologies can help address current and future animal health threats through a One Health approach.
Among its findings, the report revealed the reported number of avian influenza outbreaks in mammals more than doubled last year compared to 2023 with 1,022 outbreaks across 55 countries compared to 459 outbreaks in 2023.
The authors highlighted that, while the risk of human infection remains low, the more mammalian species such as cattle, cats or dogs infected, the greater the possibility of the virus adapting to mammal-to-mammal, and potentially human, transmission.
“The spread, prevalence and impact of infectious animal diseases is changing, bringing new challenges for agriculture and food security, human health and development, and
natural ecosystems,” said Dr. Emmanuelle Soubeyran, Director General of WOAH.
Bird flu, or high pathogenicity avian influenza (HPAI), which has caused the culling or loss of more than 630 million birds in the last two decades was one of several animal diseases to affect new areas last year.
Peste des petits ruminants (PPR), which has traditionally affected sheep and goats in developing countries, has reemerged in Europe while Africa swine fever (ASF) reached Sri Lanka, travelling more than 1,800 km from the nearest outbreaks, the report found.
Almost half of the WOAH-listed diseases notified to WOAH between 2005 and 2023 were considered a threat to human health with zoonotic, or animal-to-human infection, potential.
The report cited climate change and increased trade among the factors influencing the spread and prevalence of animal diseases. Many are preventable through a combination of vaccination, improved hygiene and biosecurity measures, but the report noted that access to animal vaccines remains uneven around the world.
“Alongside other measures, vaccination remains one of the most powerful disease prevention tools
The spread, prevalence and impact of infectious animal diseases is changing, bringing new challenges for agriculture and food security, human health and development, and natural ecosystems
available, saving countless lives, preventing economic losses and reducing the need for antimicrobial treatments,” Dr. Soubeyran added. “To limit the spread of highly damaging diseases like avian influenza, foot and mouth disease and PPR, the global community must strengthen international cooperation and ensure equitable access to safe, effective vaccines, alongside other control measures.”
Since 2006, WOAH has supported access to animal vaccines through its vaccine banks and currently operates two, one for rabies and one for PPR. As of May 2025, the WOAH Rabies Vaccine Bank has delivered almost 30 million dog vaccines to countries in Africa and Asia. However, progress towards ending rabies has stalled in recent years, with the percentage of countries reporting implementing control measures falling from 85 per cent to 62 per cent.
The report also emphasised the importance of disease prevention for reducing the need for antibiotic treatment and limiting the development of drug-resistant diseases. By 2050, antimicrobial resistance is projected to cause livestock losses that jeopardise the food security of two billion people and result in a US$ 100 trillion economic loss if urgent action is not taken.
The latest figures indicate that antimicrobial use, including antibiotics, in animals fell five per cent between 2020 and 2022, with use in Europe seeing the biggest decline of 23 per cent, followed by Africa at 20 per cent. However, one in five countries continue to use antimicrobials as growth promoters, which is discouraged by WOAH.
“The indiscriminate use of antimicrobials contributes to antimicrobial resistance, which is a major threat to both animal and human health,” said Dr. Javier YuguerosMarcos, Head of the Antimicrobial Resistance and Veterinary Products Department at WOAH. “The declining use of antibiotics in almost all regions is encouraging but further reductions can be achieved by prioritising preventative measures against animal diseases, with vaccination as an essential component of these.”
WOAH calls for investments to strengthen national Veterinary Services, greater global and regional coordination and improved disease surveillance systems to scale up effective disease control. This includes developing and implementing advanced diagnostic tools to differentiate between vaccinated and infected animals, enabling accurate disease tracking and trade transparency.
Source: WOAH
FROM GUT MICROBIOTA TO LIGHTING: INTEGRATED APPROACHES FOR SUSTAINABLE POULTRY FARMING
In Piombino Dese, in the province of Padua, farmers, veterinarians, and technicians gathered to discuss the most pressing topics in the poultry sector.
➤ Luca Bianco, MDV
The recent Tecnozoo conference sparked a lively exchange of ideas among poultry sector professionals. Breeders, veterinarians, technicians, and nutritionists convened to discuss recent advancements in critical aspects of poultry farming, such as intestinal health, shell quality, and lighting. The speakers addressed a range of topics with both scientific and practical perspectives, with innovation as the common thread. Their goal was to outline a path toward more sustainable farming practices that enhance the productive longevity of animals.
The day began with an introduction by Dr. Gianluca Favaro, General Manager of Tecnozoo, who highlighted how the company's DNA is deeply rooted in a passion and dedication to supporting professionals and operators in the sector, guiding them through their evolution and growth.
“Today, as we look to the future, our commitment is stronger than ever. We aim to be leaders in poultry farming, embracing forward-thinking approaches, investing boldly in innovation, and prioritizing sustainability.”
Dr. Enrico Tazzioli, nutritionist and head of the poultry sector at Tecnozoo, then took the stage to introduce the topics on the agenda and present the distinguished speakers. These experts will “undoubtedly enrich the conference, providing valuable opportunities for learning, idea exchange, and establishing the groundwork for an innovative and sustainable future in livestock farming.”
Dr. Alessandro Scolari, veterinarian and director of the Vallerana Diagnostic Laboratory, opened the session with a presentation on “Alternative Products for Maintaining Intestinal Health in Poultry Farming. Assessments of their impact on the microbiome." The discussion quickly turned to the significant reduction in antibiotic use over recent years, highlighting the poultry sector's commitment to sustainability: by 2021, antibiotic usage had dropped by 90% compared to 2011. The introduction underscored the
rationale for adopting alternative substances and products to combat emerging health challenges, including occasional increases in mortality during the initial weeks of life, greater group disuniformity, cases of lameness, and enterococcal spondylitis (affecting up to 1-10% of male poultry). Furthermore, there has been a rise in conditions associated with the growth of gram-positive bacteria, including necrotic enteritis, gangrenous dermatitis, botulism, enterococcosis, and staphylococcosis.
The primary focus in all cases is intestinal health, with the gut acting as the first barrier against potential pathogens. Intestinal polymicrobism, particularly when accompanied by inflamed or damaged mucosa, can result in bacterial translocation into the skeletal system - an issue most apparent in broiler chickens. This condition leads to group disuniformity and health complications, which, in turn, affect performance, shell quality, hatchability, and ultimately, the quality of the chicks produced.
The intestinal microbiota can be seen as an 'invisible army' that supports animal health. A balanced microbiome is crucial not only for maintaining intestinal health in the strict sense, but also for the absorption of essential nutrients, ensuring the production of eggs with strong shells and promoting proper growth rates. The speaker explored the various bacterial phyla within the intestinal microbiota, highlighting the numerous interactions between microbial
populations and their relationships. These dynamics can be disrupted by negative factors such as stress and disease, or positively influenced by the use of alternative products, phytobiotics, prebiotics, probiotics, postbiotics, and organic acids. Synergistic interactions have been observed between biologically active substances in alternative products, particularly between organic acids and phytobiotics. The antioxidant, antimicrobial, and mucosal protective effects of phytobiotics are enhanced by the selective antimicrobial activity of organic acids.
Finally, an advanced metagenomic analytical technique was described for the statistical quantification of intestinal bacterial populations. Using 60 stool samples, pooled in sets of 10 per group, the technique was employed to identify both beneficial changes (e.g., increases in Firmicutes and/ or Bacteroidetes) and detrimental shifts (e.g., an increase in proteobacteria) in the intestinal microbiota. These changes were attributed to factors such as stressors, environmental conditions, diseases, or interventions with alternative products. This tool is instrumental in further reducing the need for antibiotics by enhancing our understanding of the development and modification of the enteric microbiota, a key factor in maintaining the integrity and health of animals' intestines.
Dr. Murat Devlikamov from the German Phytobiotics was the second speaker of the day, discussing a key topic in sustainability and the environmental impact of poultry farms: the quality of eggshells and the nutritional strategies essential for their long-term preservation. The presentation covered several key topics, starting with the role of activated vitamin D3 in calcium metabolism, its contribution to strengthening the immune system, and its antioxidant and antibacterial effects. Active D is a product composed of a blend of selected plants, including golden oats, which contains the active form of vitamin D (calcitriol
glycosidate 1,25-OH-D3). It was demonstrated how this compound bypasses the liver and kidneys - the organs responsible for the endogenous metabolism of vitamin D3thereby enhancing calcium absorption from the intestine, its release from bones, and its reabsorption in the kidneys, even in the presence of chronic health issues. Through the presentation of several experimental studies conducted on groups of laying hens and breeding eggs, the continuous use of this product throughout the life cycle of breeding birds was recommended, in addition to normal levels of vitamin D3
The studies provided evidence of a direct improvement in eggshell quality and, indirectly, in the quality of the embryos and offspring produced. For commercial laying hens, a more targeted approach has been recommended, particularly during the final stages of their life cycle, starting from the sixtieth week. An interesting point highlighted during the presentation was the advantage of using this product in two additional phases: during weaning, to further strengthen the skeletal system of the animals, and at the onset of the laying cycle, to support the final stages of growth and the formation of medullary bone (16-20 weeks).
Several trace elements play a key role in the normal metabolic pathway of calcium. Special emphasis was placed on zinc, copper, and manganese, all of which are essential for the development of a strong egg structure. These elements enhance calcium deposition, improve shell integrity, and provide protection against oxidative stress, reducing the occurrence of thin shells. The use of the enzyme phytase facilitates the release of phosphate from phytates naturally found in raw materials used for animal feed, contributing to a reduction in phosphate levels in the feed, which is significant from an environmental impact perspective. The discussion concluded with an examination of usable calcium sources. The characteristics of these sources, including particle size and the amount to be incorporated into the feed, are
influenced by the age, physiological conditions, and food intake of the animals. The Ca:P ratio, as well as the use of larger calcium particles, increases with the advancing stages of the animal's life cycle (such as for laying hens and breeders). One of the central themes highlighted in the report was the critical role of intestinal health, especially mucosal integrity, in enabling efficient nutrient absorption. The last presentation of the day focused on an innovative technology: dynamic intelligent lighting of poultry farms. In collaboration with Once by Signify_Philips Lighting, Nice Hasani shed light on the topic by first exploring the core concepts of photobiology (the study of light's interaction with living organisms). describing light sources as a language that helps understand bird behaviour and their interactions with the environment.
There are species-specific differences in visual perception, with birds notably capable of perceiving a wider range of the light spectrum (360-750 nm) than humans. In poultry, the ratio of cones to rods is strongly skewed toward cones, at approximately 85%, indicating that birds perceive light differently from humans. They are sensitive to red, green, and blue pigments even at low intensities (as low as 8 lux), and they can also detect UV-A wavelengths. For this reason, it is essential to measure light intensity using Gallilux, a unit capable of accounting for these unique visual sensitivities. Several dynamic lighting 'recipes' were presented, designed to enhance animal performance throughout the production cycle. These lighting programs are adaptable and follow the birds' natural circadian rhythms, changing throughout the day to support their physiological and behavioural
needs. During the chick weaning phase, studies conducted at Wageningen University have shown that, in the early stages, a high colour rendering index spectrum – known as the Jungle Green Spectrum – stimulates movement as well as feeding and drinking behaviours. In the later stages of broiler growth, a blue-green spectrum referred to as 'Jungle Sky' has proven effective in enhancing flock uniformity and overall growth performance. Additionally, a monochromatic blue spectrum has been found to have a calming effect on birds during handling procedures such as transfer to laying facilities or vaccinations. Red-spectrum electromagnetic waves have been shown to play a key role in the reproductive development of laying hens by stimulating hormone release for sexual maturation. They also help regulate melatonin levels, thereby enhancing immune function and reducing stress.
"Dynamic multi-spectral lighting offers an effective solution to the challenges encountered in aviary systems. Given the complexity and high activity levels of laying hens, lighting must be both flexible and responsive to their changing behavioural and physiological needs. This system helps mitigate several undesirable behaviours, including feather pecking, cannibalism, off-nest egg laying, smothering, and uneven distribution of birds within the facility. With intelligent lighting management programs like NatureDynamics, both light intensity and spectrum (colour) are dynamically adjusted throughout the day. This supports the farmer by influencing animal behaviour - for example, encouraging egg laying with a warm white light enriched in red wavelengths, or discouraging out-of-nest
laying with a cool white or blue spectrum. All of these elements carry important economic repercussions, notably through improved quality of selectable eggs, better animal health and welfare, and a reduction in stress-related and abnormal behaviours.
These developments underscore the significant strides made by scientific research in addressing the increasingly complex demands for productive efficiency, sustainability, and animal welfare. Such innovations play a key role in enhancing the resilience of poultry, supporting longer and more consistent production cycles.
The event concluded with a productive discussion on the key issues addressed, highlighting Tecnozoo’s dedication to working closely with its customers. Through this initiative, the company has showcased its commitment to navigating the future challenges of poultry farming with both passion and expertise.
STEPPING INTO BARN DIGITALIZATION
Technification of poultry barns is a growing priority for most producers to support precision farming practices. Although such improvements can ease flock management and on-farm labor, thoughtful planning on how to integrate them into barn practices is required to ensure a full return on investment.
➤ Aitor Arrazola, Research biologist, Ph.D. in Animal Behaviour & Welfare
Moving toward high-tech barns
Investing in new technologies may appear thrilling yet raises skepticism at first sight, and a clear mindset on how barn digitalization can improve current management practices and flock performance is a must. Most of these benefits come from reducing production costs by saving labour time, automating processes, and quickly spotting potential threats to poultry health, welfare, and performance. Early technification of poultry barns started with automation of feeder throughs and water lines to optimize the use of feed and water efficiently while avoiding spillage into litter, yet still developing to maximize nutrient intake and reduce waste. Further digitalization of housing systems allowed producers to adjust automatically environmental conditions throughout the flock’s lifetime, regardless of outdoor weather, particularly in temperate climates where summer temperature and humidity surpass dangerous thresholds and harsh winter conditions put at risk birds’ survival. Even nowadays, integrated advancements in heating, cooling, and ventilation systems are becoming more effective at keeping environmental conditions within comfortable thresholds to support livability and proper flock performance, allowing poultry barns to operate worldwide and yearlong while reducing thermal stress and related mortality. Similarly, centralized control of lighting programs enables greater control over daylength, light intensity, and light quality to boost feed intake, synchronize lay onset, or manage behavioural problems during rearing and lay. All these systems generate a large volume of data periodically useful to analyze how indoor conditions impact production outcomes (for example, during extreme weather events such as heat waves or heavy snowstorms).
Barn sensors have recently gained importance to track indoor environmental conditions and ensure housing systems provide an optimal climate to meet performance objectives and good health. Besides temperature and relative
humidity sensors, new technologies in the market allow for more advanced air quality readings such as concentration of ammonia, greenhouse gases, and particle matter, which are responsible for airborne diseases in poultry and staff. This information can further help refine on-farm practices to maintain levels within safety recommendations and develop strategies to lower emissions. Additionally, sensor devices are also commercially available to measure feed bin and water tank content to help foresee new refills in a timely manner. This real-time tracking overall provides peace of mind when things run smoothly and allows producers to check/adjust barn indoor conditions and control energy, water, and feed consumption even when not physically present in the barn. Most of these systems also permit users to set up phone alerts when parameters rise above or drop below given values which aids in spotting promptly equipment malfunctions or harmful conditions so personnel can take quick action before consequences scale up.
In the last decade, the field of artificial intelligence has
been making its way into poultry production systems advancing technology tools to process sensory data (visual, auditory or environmental) instantaneously and deliver in real time desirable outcomes for which the model has previously been trained. Some commercially available software can help manage large poultry flocks by automatically monitoring production outcomes (laying rate, body weight, number of birds), spotting equipment malfunctions, checking resources utilization, and detecting subtle behavioural changes like moving and activity patterns, drops in feeding and drinking, and distress calls. Surveillance cameras powered by computer vision are bringing new opportunities to track flock health and performance nonstop and help prevent disease and behavioural outbreaks due to early detection. Same as sensor alerts, flagging these on-farm complications quickly allows producers to enhance the decision-making process for timely interventions and act promptly before greater endeavours are needed.
Some thoughts beforehand
Digitalization can increase flock productivity by automating processes and helping detect problems rapidly as well as areas for improved effectiveness. Such benefits purely rely on 1) knowledgeable, skillful personnel on poultry-specific care and tech-savvy, 2) staff capacity to intervene on-time when needed, 3) clear awareness on how technology can ease routine flock management, and 4) continuous maintenance and supervision to verify equipment operates accordingly to
expectations. Indeed, digitalization of poultry houses must be seen as an aid to enhance current on-farm practices to ultimately improve flock welfare, health, and performance rather than as a tool to elude proper management practices. For example, flock/barn alerts are pointless if not followed by timely corrective measurements by skillful, knowledgeable caretakers. As well, emergency action plans have to be properly laid out and well known by staff so if alerts go off personnel is aware of the protocol. Finally, and most importantly, this economic investment of barn digitalization must pay off in the long run to make it profitable. In other words, the benefits of new technology implementation (e.g., personnel satisfaction, improvements in flock performance, and ease of management) ought to outweigh the cost of initial acquisition and installation, staff training, and ongoing operating and maintenance requirements. Therefore, next steps into barn digitization should aim to overcome current production cost and flock performance limitations.
THE REGIONAL STRUCTURES OF WORLD EGG PRODUCTION IN 2023
In December 2024, the FAO published statistics on egg production at continent and country level for the year 2023, making it possible to present a new overview of the regional structures of world egg production. This article documents the shares of the individual continents and the leading countries in world egg production.
➤ Hans-Wilhelm Windhorst, Professor Emeritus, University of Vechta, Germany
Asia dominated global egg production
In 2023, 92.7 million tonnes of hens’ eggs were produced worldwide1. Asia accounted for 57.9 million tonnes or 62.5%. America followed with 18.0 million tonnes.
Figure 1 compares the continents’ shares in the global population with their shares in world egg production. The large discrepancy in Africa is remarkable. While it accounted for 18.3% of the world’s population, it only achieved 4.2% of egg production. Oceania’s share in the global population was also higher than its share in egg production. In the other three continents, the ratio was reversed, with the difference being significantly greater in Europe and America than in Asia.
Of the ten countries with the highest egg production in 2023, five were located in Asia, four in the Americas and one in Europe.
Figure 2 shows that the three countries with the highest population, China, India and Indonesia, together accounted for 48.6% of the global production volume, with China occupying an unchallenged first position. It is difficult to decide, however, whether the production figures
▲ Figure 1 – The shares of the continents in the global population and global egg production in 2023 (design: A.S. Kauer based on FAO data)
1 The value as published for Europe is incomplete as there are no data for France and Poland. The value used in this paper includes the production of the two countries.
▲ Figure 2 – The share of the ten leading countries in global egg production in 2023 (design: A.S. Kauer based on FAO data)
published for China were actually achieved or whether they were more likely to be planning figures. Unofficial information indicates that the individual provinces sometimes report excessively high figures to the central statistics office in order to make an impression on the government by over-fulfilling their planning targets.
Considerable differences in the regional concentration2 of egg production
▲ Figure 3 – The regional concentration in egg production at continent level in 2023 (design: A.S. Kauer based on FAO data)
The next step in the analysis is to document the regional structures in the individual continents. Figure 3 shows remarkable differences in the regional concentration of production. The highest degree of concentration was in Oceania with 98.6%, which was accounted for by just five countries. This was followed by America and Asia, each with shares of over 90% of the top ten countries. The regional concentration was significantly lower in Africa and Europe. There was a more even distribution. However, the detailed analysis will show that some countries also played a major role in these two continents.
Degree of concentration - a reflection of population size?
When analysing the regional concentration in the individual continents more closely, it becomes obvious that it partly, but not always, reflects the population distribution. This is obvious in Oceania. Australia and New Zealand accounted for 90.4% of egg production but only for 70% of the
2 Regional concentration is defined as the share of a few countries in the continent’s total production.
– The share of the ten leading countries in the egg production of the respective continent in 2023 (design: A.S. Kauer based on FAO and EUROSTAT data)
population. Papua New Guinea, which shared almost a quarter in the continent’s population, contributed only 5.2% to egg production, while Fiji, sharing 18.3% in production, accounted for only 2% of the population. It is obvious that other factors also must have played a role. In Papua New Guinea, the low level of the economic development was the decisive factor, in Fiji it was the economic importance of international tourism.
Figure 4 documents the degree of concentration for the other four continents. In Asia, the three most populous countries held the leading positions. Together they accounted for 77.3% of egg production and 66% of the population. Japan shared 4.2% in egg production but only 2.6% in the population. The opposite was true for Pakistan, which contributed only 1.9% to egg production while sharing 5.3% in the population. In the Americas, the three countries with the highest populations also were in the top positions. The USA, Brazil and Mexico together accounted for 66.1% of the continent’s population and 72.6% of egg production. The USA, which ranked in first place, shared almost exactly one third in the continent’s population and 36.2% in egg production. The ratio was almost balanced. The situation was similar in Brazil, with 19.5% of the population and 18.9% of egg production. The high per capita consumption, which was 392 eggs in 2023, explains why Mexico accounted for 17.5% of egg production in the Americas while sharing only 12.5% in the population. Colombia, which ranked
fourth in egg production with a share of 5.6%, has shown a very dynamical development over the past three decades. Egg production rose from 278,000 tonnes to over 1 million tonnes. Sharing around 1% in the world population as well as in global egg production, the ratio was balanced. With a population of almost 750 million, Europe accounted for 9.2% of the world’s population in 2023, but with a production volume of 12.4 million tonnes for 13.4% of global egg production. The difference can be explained by the high development level of the egg industry, which is characterised by the use of hybrid hens with a high laying performance, high-quality feed and competent veterinary care for the hen flocks.
Of the ten leading countries, four were located in Eastern Europe, three in Southern Europe and three in Western and Central Europe. Russia, the continent’s most populous country with 144.8 million inhabitants, corresponding to a share of 19.4%, accounted for 21.8% of total production with a volume of 2.6 million tonnes, thus showing an almost balanced ratio. In the following countries, with the exception of Spain and Ukraine, the share in the continent’s population was higher than in egg production. The highest discrepancy showed Germany. A share of 11.3% in the population was offset by 7.9% in egg production. While production in Germany declined, it increased in Spain, following the switch from conventional cages to alternative housing systems4. The top five countries shared 50.2% in Europe’s egg production.
The largest discrepancy between the share of 18.3% in the global population and the contribution of only 4,2% to global egg production showed Africa. This was mainly due to the large differences in the economic development of the countries. Of the 51 African countries, 31 belonged to the group of least developed countries. In nine of the ten leading countries in egg production, the share in the continent’s population was lower than in the production volume. The difference was particularly large in Egypt, South Africa, Morocco and Algeria. This was also the case in Nigeria, Africa’s most populous country with 213 million inhabitants. These five countries had an efficient egg industry, while in the majority of the other countries extensive forms of laying hen husbandry prevailed, in most cases with less efficient laying hen breeds. As a result, despite the comparatively low overall regional concentration of 78.3%, the top four countries alone accounted for 53.3% of total production, while the other 47 countries shared only 46.7%.
Summary and outlook
Table 1 compares the shares of the ten leading countries in global egg production with those in the world’s population. Some interesting correlations appear when a quotient is calculated from the two percentage values. Although China and India had almost the same population in 2023, egg production in China was four times higher than in India. In China, the number of large vertically integrated companies has risen considerably over the past decade, often subsidised by the central government. Nevertheless, eggs continue to be produced predominantly in medium-sized farms, with fewer than 50,000 hen places. It can be assumed that these will become increasingly less important. In India, there were only a few large companies with a high technical standard. They mainly supplied urban agglomerations. In rural areas, backyard farms with only small flocks of mostly local breeds continued to dominate. Due to the low biosecurity of these farms, it is not surprising that outbreaks of the avian influenza virus occur time and again. In Mexico and Indonesia, the shares in global egg production were twice as high as in the world’s population. It should be considered, however, that Indonesia’s population was more than twice as large as that of Mexico. The poultry industry developed extremely dynamically in both countries. In Indonesia, egg production increased from 1.2 million tonnes in 2013 to 6.5 million tonnes in 2023, i. e. by 531%; in Mexico from 2.5 to 3.2 million tonnes or by 23% in the same period. Vertically integrated companies dominated in Mexico. With Proteina Animal, it had the second largest company worldwide. In Indonesia, the Thai group - CP Charoen Pokphand Indonesia – was in a leading position. As in Mexico, laying hens have so far been kept almost exclusively in conventional cages. In Indonesia, however, there are signs of a switch to alternative housing systems. Avian influenza is endemic in both countries.
■ Table 1 – Share of the top ten countries in world egg production and world population in 2023; data in % (source: own calculations based on UN and FAO data)
China
India
Indonesia
USA
Brazil
Mexico
Russia
Japan
Turkey
Colombia
The table shows that the ratio of the respective shares in Colombia is balanced. The differences are also small in Turkey and Brazil. Both countries are likely to increase their egg production significantly in the coming years, due to the rising domestic demand and a stronger focus on exports. In Russia, on the other hand, there are indications of a further decline in production. As India will have to increase its egg production in the current decade due to the increasing per capita consumption and a growing population, the regional concentration in global egg production will further increase.
Data source and supplementary literature
FAOSTAT: https://www.fao.org/faostat/en
Windhorst, H.-W.: The forgotten continent: Patterns and dynamics of the African egg industry - Laying hen inventory and egg production. In: Zootecnica International 42 (2020), no. 9, p. 24-27.
Windhorst, H.-W.: The Champions League of the egg producing countries. In; Zootecnica International 43 (2021), no. 1, p. 26-29.
Windhorst, H.-W.: An insight into the Spanish poultry industry – Hen eggs. In: Zootecnica International 44 (2022), no. 6, p. 26-29.
Windhorst, H.-W.: The remarkable dynamics of the global poultry industry: 50 years in retrospective – Global egg production and trade. In: Zootecnica International 45 (2023), no. 6, p. 20-28.
Windhorst, H.-W.: Meat and eggs, 2012-2022: was it the decade of Asia? In: Pig Progress 40 (2024), no. 9, p. 6-10.
PERCH USAGE IN LAYING HENS
Modern poultry farming is seeing a significant shift towards higher welfare standards. This is due to the demand of the public for welfare-friendly products and to ensure the sustainability of the poultry industry.
➤ Manita Kafle, Graduate Research Assistant, and Tom Tabler, Professor Department of Animal Science, University of Tennessee
The Five Freedoms have been the basis of animal welfare since the 1960s. It states that animals are in a good state of welfare when they have freedom from hunger and thirst; freedom from discomfort; freedom from pain, injury, and disease; freedom from fear and distress; and freedom to express normal behaviors (FAWC, 2009). Laying hens are motivated to perform normal behaviors such as perching, stretching, pecking, scratching, nesting, and dust bathing. One method of ensuring the welfare of laying hens by allowing them the freedom to express normal behaviors is through providing sufficient space and appropriate resources. The laying hen industry is adopting alternative housing systems like aviaries, which offer more space and resources than conventional cage systems. Intending to provide freedom and opportunity for laying hens to express behaviors and enhance welfare, the European Union (EU) directive took a significant step by banning the use of conventional battery cages from 2012 onwards (Council Directive, 1999).
A key component of the alternative housing system is perch provision. Perching is the antipredator behavior
observed in wild fowl (Gallus gallus) that involves perching on elevated structures like tree branches (Newberry et al., 2001). This behavior persists in domestic fowl (Gallus gallus domesticus) such as cage-free laying hens despite their domestication in indoor housing systems in the absence of non-human predators (Newberry et al., 2001). Perching is a highly motivated behavior in hens which is supported by compelling evidence indicating that hens showed signs of agitation when perches were inaccessible (Olsson & Keeling, 2000). Additionally, the strong motivation for roosting is highlighted by research demonstrating that hens actively utilized a push-door to access a perch (Olsson & Keeling, 2002).
Perches
An adequate perch for laying hens refers to one that birds can grip with their feet securely, providing a vantage point for observing the surroundings, and is elevated to promote natural roosting behavior (EFSA Panel on Animal Health and Animal Welfare - AHAW, 2015). Hens use perches to sit, stand, rest, or sleep. The provision of elevated perches is a priority for laying hens (Olsson & Keeling, 2002). But merely offering perches is not sufficient for welfare enhancement; perches must be provided in a way that ensures equal and
easy access for all hens (EFSA Panel on Animal Health and Animal Welfare (AHAW), 2015). According to Council Directive (1999), the minimum standards for the protection of laying hens were set including the perch-related requirements, which are as follows:
• Provision of adequate perches
• Perches without sharp edges
• Perch space of at least 15 cm per hen
• Perches must not be mounted above the litter
• The horizontal distance between perches must be at least 30 cm and the horizontal distance between the perch and the wall must be at least 20 cm.
Perching impacts
Over the years, many studies have been conducted to evaluate the effect of rearing with and without perches, and its impact on the birds’ health and welfare. The use of perches during the rearing environment has shown both beneficial and adverse outcomes.
Perches are vital for the physical development of birds, as they encourage jumping and flying behaviors, thereby supporting their overall fitness and growth (Campbell et al., 2016). Hens provided with perches typically have stronger bones compared to those without access to perches (Fleming et al., 1994). The use of perches contributes to skeletal development and increases leg bone strength and muscle growth in birds through continuous movement in the perches (Kiyma et al., 2016; Leyendecker et al., 2005). Hens with perch access compared with no perch access during the egglaying period effectively reduced abdominal fat deposition (Jiang et al., 2014). Perch usage lowers floor stocking density and improves foot health and cleanliness (Kiyma et al., 2016). Furthermore, the provision of perches reduces the level of aggression and fear within commercial laying hen flocks (Donaldson & O’Connell, 2012); promotes the expression of positive comfort behaviors such as scratching, leg stretching, body shaking, wing fapping, (Chen et al., 2014); minimizes the occurrence of feather and vent pecking from aggressive and dominant hens; and ensures increased security (Gunnarsson, 1999; Kiyma et al., 2016). Utilizing perches led to increased body weight and body condition scores in hens while maintaining egg quality, feather coverage, foor egg proportions, and egg-laying performance (Donaldson & O’Connell, 2012). Hens raised without early access to perches have impaired spatial cognitive skills required for navigating three-dimensional spaces, which might affect later perching abilities (Gunnarsson et al., 2000). In essence, perches enable birds to engage in natural behaviors, thereby fostering their health and welfare (Pickel et al., 2011). However, some major health and welfare concerns are related to perch usage. Introducing perches into a housing system has been found to impact two main issues: keel bone damage and footpad disorders (Hester, 2014; Käppeli et al., 2011). Damaged keel bone may be painful and affect the
The way perches are built can significantly affect the perching behavior, welfare, and productivity of hens
mobility of the hen (Nasr et al., 2012, 2013). Differences in the housing system are linked to differences in rates of keel bone damage. The prevalence of keel bone issues is high in alternative housing systems such as aviaries, as they provide greater opportunity and freedom to move and fly, posing a significant welfare challenge in contemporary laying hen farming practices, but is also present in conventional cage systems (Käppeli et al., 2011; Petrik et al., 2015; Wilkins et al., 2011). The tendency of increased risk of keel fractures is positively linked to the height of the perches (Wilkins et al., 2011), suggesting the considerable impact of collisions. Furthermore, perch usage can result in unstable footing while flying to/from perches (Scholz et al., 2014). Prolonged pressure load on the footpad can result in serious foot pad disorders including bumble foot and foot pad hyperkeratosis.
General consideration on perch designs
The way perches are built can significantly affect the perching behavior, welfare, and productivity of hens. When implementing elevated perches, accessibility is crucial. Good perch designs should allow hens to access the perch comfortably without restrictions, ensuring birds can fly or jump freely (Struelens & Tuyttens, 2009). Therefore, it is advisable to introduce stepwise perch designs or combine higher perches with lower levels to facilitate hen access to elevated perches. Perches should be easy to clean and disinfect (Sandilands et al., 2009). Furthermore, a welldesigned perch should mitigate the risk of unstable footing and injuries such as bone fractures and keel damage (Scholz et al., 2014), thereby safeguarding the health and welfare of the hens and promoting their natural behaviors.
Perching materials
Different commercial perch materials are available in the poultry industry such as wood, steel, plastic, metal, vinyl padded, and polyurethane. Wood is commonly used due to its cost-effectiveness, but it poses challenges such as susceptibility to red mite infestations in the presence of cracks and holes and is often difficult to clean (Hester, 2014). Metal and plastic perches are easier to clean and are less prone to mite infestations with closed joints but can be slippery. Vinyl padded perches are favored by hens for their enhanced grip, providing better stability for hens (Struelens & Tuyttens, 2009). Polyurethane perches stand out for their efficacy in improving footing stability as evidenced by hens spending more time on polyurethane perches as compared to plastic and metal perches (Pickel et al., 2011). Moreover, perches with polyurethane have demonstrated potential in reducing footpad disorders and minimizing keel bone fractures and deviations (Stratmann et al., 2015). Therefore, the importance of perch material selection in promoting both the physical comfort and welfare of laying hens cannot be overlooked.
Perch height
The height of the perches is considered an important factor. Laying hens seek elevated perches during the day as well as at night. Hens prefer lower-height perches during the daytime and higher-height perches during the nighttime (Struelens & Tuyttens, 2009). The motivation to seek elevation is particularly strong at night when hens select a
site for resting or sleeping. Perches of different heights for day and nighttime can help in promoting perching behavior. Higher perches help hens monitor the environment and avoid disturbances from the surroundings.
Research has shown that perch usage among laying hens tends to rise as the height of the perches increases (Brendler et al., 2014). Hens should be provided with perches that require no more than 80 cm to jump vertically, horizontally, or diagonally to reach or leave the perches (EFSA Panel on Animal Health and Animal Welfare - AHAW, 2015). Hence, careful consideration of perch height is vital to optimize perch usage.
Perch shape and diameter
Perches come in different shapes such as round, oval, square, and rectangular. The shape of perches have a significant impact on peak forces experienced by the keel bone and foot pad of laying hens (Pickel et al., 2011). Round and oval-shaped perches provide less contact area and exert higher peak pressure on the keel bone and foot pad than square or rectangular perches with sharp edges (Pickel et al., 2011). However, sharp-edged perches could contribute to signifcant footpad disorders, such as bumblefoot and toe hyperkeratosis (Liu et al., 2018). That is why the EU directive mandated that perches must not have any sharp edges.
Perches with higher diameters provide larger surface area for the attachment of keel bone and footpad with better stability in hens as compared to lower diameters (Pickel et al., 2010). A perch of width between 3 and 6 cm is recommended for better stability and to reduce peak force in the keel and foot
pad (EFSA Panel on Animal Health and Animal WelfareAHAW, 2015).
Conclusion
Enhancing poultry health and welfare through welldesigned perching options is crucial. Educational programs aimed at producers should emphasize the benefits of perch utilization and the importance of optimal design. Poultry producers should prioritize the incorporation of adequate space and opportunities for perching within their housing systems. This aligns with the natural behavioral needs of laying hens and can significantly contribute to their welfare. Perching allows hens to exhibit instinctual behaviors, such as roosting and observing their surroundings, promoting a sense of security and comfort. However, it’s not enough to merely include perches in poultry housing. Careful attention must be given to various factors during the design phase. The choice of perch material, its shape and height, and the overall space allocation are all critical considerations. These elements can impact not only the usability of the perches but also their safety and effectiveness in promoting natural behaviors and physical health.
References are available on request
By courtesy of The University of Tennessee Institute of Agriculture and UT Extension
PRIMING YOUNG BIRDS FOR GUT HEALTH AND RESILIENCE
This brief review focuses on the types of fibre that the nutritionist should be considering and how a phase feeding strategy should not only take into account the changing needs of the bird as it ages, but also the changing needs of the microbiota if good intestinal health is to be maintained.
➤ M.R. Bedford, AB Vista, Marlborough UK
In a Google search the term “Gut health” appeared in 19,400 pdf articles published from 1st Jan 2020 to the 3rd October 2024 and the AI generated summary suggested the main factors influencing gut health included:
• Diet – Nutrients and additives
• Water quality
• Environmental temperature, humidity
• Management
• Pathogen exposure
• Immune system status.
Clearly this topic is of great interest and all the factors above are important and need consideration. This is especially the case in regions where antimicrobial growth promoters (AGP’s) have either been banned or removed from feeds on a voluntary basis. In such places, the incidence and severity of intestinal disorders and disease has markedly increased, hence the desire to manage gut health has intensified. Animal husbandry (which is involved in factors 2-5 above) plays by far the greater role in determining the likelihood of such disorders, but diet also has an influence. Most dietary interventions intended to manage gut health focus on the avoidance of antinutrients, toxins and excess protein, and the provision of anti-microbial or immune system-stimulatory products. Surprisingly, there is only limited focus on the role that fibre plays in maintaining gut health in broilers (and far more interest in the antinutritive role it can play) and yet it is probably the single most important dietary determinant of intestinal health. One reason for this situation is that the understanding of fibre is poor, made worse by the fact that the routine methods we use for determination of fibre have little value in describing the biological effects it conveys. As such, the fibre content and quality of a diet does not have the same level of scrutiny that other nutrients enjoy, e.g. amino acids. A far better understanding of the dietary content of the different components of fibre and an allocation of biological effect to each is essential if nutritionists are to take full advantage of
its value in AGP-free diets. This paper focuses on why fibre is so important, what types of fibre we should consider, and how to ensure that the bird starts well and “learns” how to adapt its microbiota over time and as quickly as possible to utilise fibre as a health promoting substrate.
Fibre chemistry
Ideally, the nutritionist should be aware of the fractions of fibre that are rapidly, moderately, and slowly fermented and those fractions which have direct positive (e.g. gizzard development) or negative (e.g. viscosity, accelerating feed transit) effect on the digestive process. Unfortunately, even when the feed industry does consider fibre, it tends to focus on measurements based on methods developed over 150 years ago. This identifies dietary fibre as either crude fibre or nitrogen free extract. Neither of these categories convey any indication of structure or functionality. More sophisticated methods developed in the latter half of last century split fibre components into those fractions remaining after a wash with acid or neutral detergents. This does yield more useful information regarding the quantities of “intransigent” and potentially fermentable fibre components but this information is still quite rudimentary. More recent methods to separate the fibre into:
• Oligosaccharides
• Pectins
• Hemicellulose
• Cellulose
• Lignin.
This further categorization of fibre is somewhat helpful in identifying whether it might be fermented rapidly, slowly, or not at all, but information is still lacking. Further fundamental characteristics of fibre which influence the effects that it will exert in the intestinal tract of the monogastric are still overlooked. The solubility and size of the fibre along with its complexity of structure have an enormous influence on whether, and if so, where in the intestinal tract, it will be fermented. Each of these characteristics are discussed in more detail below.
Fibre solubility and size
Recent work has demonstrated that only soluble material and extremely small particulates get into the caecum of the chicken (Vanderghinste et al., 2024). The particulates on average are less than 50 microns which limits entry to a very small fraction of the insoluble ileal indigesta. It also suggests that technological processing of the diet likely has little influence on caecal entrance of insoluble fibrous materials. Indeed, to all intents and purposes the caeca should be seen as an organ which mostly processes soluble fibre, thus processes or additives which alter fibre solubility are potential tools for optimising large intestinal health in poultry.
Coupled with the solubility of the fibre is its molecular size. Very small molecules, oligosaccharides, are far more fermentable than their larger counterparts as the latter have to be disassembled before they can be absorbed into the bacterial cell and metabolised (Figure 1). The larger the molecule, the longer the time needed for disassembly. The initial rate of fermentation is therefore proportionately linked to the size of the molecule but there are two further considerations.
The first is that some oligosaccharides have recently been shown to act as signalling molecules in addition to them
being readily fermentable. These “stimbiotics”, such as xylo- and arabinoxylo-oligosaccharides (XOS, AXOS) have been shown to dramatically influence the metabolic activity of many significant bacterial species involved in the deconstruction, transport and metabolism of fibre. (Amir et al., 2023). As such they not only increase the capacity of the caeca to degrade and effectively “digest” fibre on behalf of the host, but they also accelerate the development of such a microbiota structure so that the ability to degrade fibre is established earlier in the life of the host. Thus, the evolution of the large intestinal microbiota from a predominantly starch and protein degrading structure to a more stable fibre degrading structure is enhanced and stabilised. This concept is discussed in more detail below. The second consideration is that very large and soluble polysaccharides, in addition to being sources of more slowly fermented fibre (which is desirable as noted in the next section), they may be detrimental due to their ability (in some cases) to aggregate and form viscous complexes. This can reduce digestibility of all nutrients dramatically and with regards to caecal fermentation and health, the key issue here is whether protein digestion is compromised to the point that the caeca is exposed to excessive soluble protein ingress. Putrefaction of this material can significantly degrade fibre fermentation and result in loss of intestinal integrity and even disease outbreak.
▲ Figure 1 - Schematic of the influence of molecular size and solubility of fibre on its function and fermentability.
Complexity of fibre structure
The structural complexity of fibre influences the rate at which it can be depolymerised and subsequently metabolised. In general, linear NSP’s with very few substitutions can be depolymerised rapidly by just a single, relevant endo-acting enzyme. However, the presence of a few substitutions can limit access of the endo-enzymes to the backbone and thus reduce the rate and extent of depolymerisation. As substitution density and complexity increases, the rate of depolymerisation decreases and the size of the fragments produced increases. Highly substituted fibre demands a significant array of ancillary enzymes that need removal before the backbone can be attacked and the desired oligomers produced. The production of this wide array of ancillary enzymes requires the development of a complex and co-ordinated microbiota which takes time to develop. In general, the most complex fibre structures are fermented only once the “easy to ferment” material has been exhausted. A schematic of fibre complexity is shown in Figure 2
Evolution of the host microbiota
At hatch the intestines of the bird are sterile. In modern poultry production the newly hatched chick gets its initial
inocula at the hatchery, during transport to the growing sheds and from the sheds themselves including the feeders (and feed) and waterers and numerous other sources. As a result, the structure of the intestinal microbiota is far more variant between individuals and flocks and less suitable for the development of a healthy microbiota compared with nature, where the hens caecal droppings around the nest provide an inocula of relevance to the environment in which the bird has grown. The development of a stable and beneficial microbiota is therefore not assured, and given the absence of prophylactic antibiotic use in many geographies, the opportunities for pathogens to establish are significant. Thus, the strategy for the industry is to ensure a smooth and rapid transition from initial colonizing bacteria to a healthy fibre fermenting community as rapidly as possible. The evolution of the caecal microbiota is dependent not only upon the initial inocula, but also the substrates to which the bacteria are exposed. The material entering the caeca are the soluble indigesta from the ileum and given the digestive process in the neonate is not fully developed, this means that the caecal residents have a range of substrates to “chose” from, including starch and protein in relative abundance. The availability of such rapidly fermentable substrates favours the development of species which can utilise such material at the expense of those that specialise on more intransigent fibre sources. However, with time the chick significantly increases its ability to digest starch and protein, thus progressively limiting their delivery to the
▲ Figure 2 - Schematic of increasingly complex soluble fibre structure starting with an unsubstituted backbone and ending with multiply substituted backbone with phenolic linkages between backbones.
caeca. Coupled with the development of the host digestive capacity, there is also a development of the small intestinal microbiota which effectively remove not only starch and protein but also the more readily fermentable NSP (Davies et al., 2024). At the same time they release soluble NSP from the cell wall structures (Lee et al., 2017) and provide the caeca with more substrate, some of which is highly fermentable (Bai et al., 2024). As the ileal populations mature the supply of soluble fibre to the caeca stabilises with the majority being represented by arabinoxylan, galactan and mannan. Comparison of the sugar composition of ileal soluble fibre with that of the caeca suggests the arabinoxylan is by far the preferred substrate at 42 d of age (Lee et al., 2017) and hence the goal should be to develop arabinoxylan fermentation capability as soon as possible. It is most important to recognise that an ideal feed should contain rapidly, moderately and slowly fermented fibre so that all regions of the intestine are presented with substrate. As the bird ages and the caeca mature the availability of greater quantities of slowly fermented fibre may be critical for continued caecal health.
Priming of the caecal microbiota
From the points made above, it is clear that the sooner the caecal microbiota are adapted to ferment arabinoxylans,
the smoother the transition from the neonatal microbiome to a stable adult microbiome. It has been known for a while that exposure of a broiler to a xylanase from first day of age markedly increases the ability of the caecal microbiome to utilise xylose, XOS, soluble arabinoxylans and even insoluble arabinoxylans (Bedford and Apajalahti, 2018). This clearly suggests that priming of the caecal microbiota is indeed possible, but it is not clear what it is that initiates the change. Prebiotic supply (through degradation and thus dissolution of insoluble NSP coupled with
depolymerisation of high molecular weight soluble NSP) has been proposed as one of the 3 key mechanisms by which NSPase’s function in addition to viscosity reduction and cell wall degradation. Such supply of additional soluble NSP alone would presumably encourage the growth and activity of NSP degrading bacteria in the caeca, which could explain such effects. Indeed NSPases, particularly xylanases, should be of benefit in diets which are limited in soluble fibre content (eg Maize-soy and in particular sorghum-soy diets). However, whether simply supplying additional substrate is sufficient to drive a smooth caecal population transition before the alternative and rapidly disappearing substrates (protein and starch, e.g.) are exhausted, is not clear. Addition of 0.25% AXOS was shown to enrich Bifidobacteria and improve growth rates of broilers fed wheat-based diet suggesting that quantitatively supplying such a substrate may be all that is needed (Courtin et al., 2008). Indeed, addition of 0.5% AXOS to a wheat-based diet resulted in a significant acceleration of NSP fermentation in broilers compared with the control, suggesting not only was the AXOS fermented but also some of the structural NSP in the diet (Bautil et al., 2020). The AXOS was termed a “kickstarter” as it enabled NSP hydrolysis in the ileum and fermentation in the caecum at far younger ages than could be achieved on the control diet. However, concurrent work had shown such effects were possible with much lower addition rates of XOS – 60 g per tonne of feed. This is far too low an inclusion rate to result in a meaningful increment in fermentation activity directly (Ribeiro et al., 2018). Indeed, in this work it was suggested added XOS or AXOS generated by exogenous enzymes may alter the metabolism of the resident microbiota. Recent work has corroborated this hypothesis where it was shown that supply of as little as 50 g per tonne of feed of a XOS (DP2-6) markedly increased the presence of SusC and SusE proteins involved in the breakdown of complex polysaccharides, binding of the oligosaccharides produced at the outer membrane and transport across the periplasmic space (Amir et al., 2023). Thus it now appears that some of the products of NSPases may not only be prebiotic substrates, but also signalling molecules or “Stimbiotics” (Gonzalez-Ortiz et al., 2019), which radically alter the ability of the caecal microbiota to ferment fibre when present at very low levels in the diet. Whilst these molecules can be produced by xylanases in wheat based diets, they are not produced in corn based diets (Kouzounis et al., 2021), and hence for the stimbiotic effect in corn based diets, external XOS may have to be added. It is likely that differences in xylan substitutions limit the ability of xylanases to break AX down to the relevant DP2-6 XOS hence stimbiotic oligosaccharides are not produced. Indeed not all wheat samples release XOS when treated with a xylanase (Whiting et al., 2023) and hence XOS should be added as an insurance if the stimbiotic effect is to be guaranteed.
Priming – The challenge and problems for the industry
As the bird and the microbiota mature, the number of different carbohydrate sources entering the caeca become reduced such that at maturity the majority of the fermentable carbohydrate is xylan (Lee et al., 2017). If the caecal resident microbiota fail to adapt in time to use the AX then protein becomes the fermentation substrate of choice (Apajalahti and Vienola, 2016) which results in production of destructive metabolites and increases the chance of disease outbreak. The challenge is to ensure a rapid and smooth transition towards a microbiota capable of utilising the major fibre substrate in the caeca, namely AX, which can be achieved by educating or kickstarting their metabolism as soon as possible by provision of the necessary signalling molecules, namely the AXOS or XOS with low degrees of polymerisation. Once activated, the challenge for the industry is to maintain an adequate flow of soluble AX into the caeca, since insoluble material will likely not be able to enter due to the significant sieving effects of the caecal villi at the caecal entrance (Vanderghinste et al., 2024). It is proposed that a standard corn or sorghum soy diet may be lacking in this regard due to the paucity of soluble AX in each of these grains and as such the utilisation of a xylanase capable of degrading insoluble AX into soluble AX, particularly in the grower and finisher
diets where fermentation capacity is maximised, is likely of great benefit. Thus a combination of a XOS or AXOS with a xylanase likely seems to be the most robust strategy for maintaining caecal health particularly in corn or sorghum based diets and perhaps even in wheat based diets where generation of XOS from a xylanase cannot be guaranteed (Whiting et al., 2023).
Conclusion
Nutritionists need to consider the evolution of the needs of the caecal microbiota in their diet formulations more than ever now that the “cure all”, i.e. prophylactic antibiotics, are no longer available in many parts of the world to deal the upsets that occur when fermentation balance is lost. A long-term approach will likely be most successful whereby the nutritionist not only matches the nutrient contents of the diet to suit the requirements of the bird during each phase, but also considers the quantity and type of fibre that should be present in order to encourage the establishment and development of a beneficial caecal microbiota.
References are available on request
From the Proceedings of the Australian Poultry Science Symposium 2025, by courtesy of the Poultry Research Foundation
CONCURRENT INFECTION OF HISTOMONAS MELEAGRIDIS AND EIMERIA
MELEAGRIDIS IN A TURKEY FLOCK
Blackhead disease (histomoniasis) in turkeys is one of the protozoan diseases sporadically documented in commercial turkey production facilities. Histomoniasis may induce mild, moderate, or severe mortalities up to 80-100%. With the absence of commercial vaccines and prophylactic/therapeutic drugs to combat histomoniasis, epidemiology studies provide critical insights into the pathogenesis of this disease. This clinical case report details concurrent infection of Histomonas meleagridis and Eimeria meleagridis in a turkey barn.
➤ Vijay Durairaj1, Steven Clark2, Emily Barber1 and Ryan Vander Veen1
Blackhead disease (histomoniasis, histomonosis, enterohepatitis) in turkeys is caused by an anaerobic protozoan parasite, Histomonas meleagridis (1). Turkeys are highly susceptible to histomoniasis compared to chickens. Heterakis gallinarum, the common cecal worm of gallinaceous birds, acts as an intermediate host for H. meleagridis. Earthworms serve as a paratenic host for H meleagridis. Vectors such as insects, flies, and fomites have been documented as carriers of Heterakis gallinarum eggs. H. meleagridis affects the ceca and enters the hepatic portal circulation resulting in necrosis of liver. The mortalities are highly variable in histomoniasis field outbreaks. Mortalities may be mild, moderate, or even severe causing up 80100% mortalities (2). Several factors are associated with increased mortalities, including virulence of the isolate, age of the birds, season, immune status of the birds, and concurrent infections (3,4). Histomoniasis associated mortalities, production losses and carcass condemnations cause substantial losses to the turkey industry (5). For decades, blackhead disease was managed by administration of antihistomonas drugs. Due to food safety concerns and several other reasons, prophylactic and therapeutic measures for histomoniasis were either banned or withdrawn from the global market (6). Currently, there are no commercial vaccines or efficacious prophylactic/ therapeutic drugs to combat histomoniasis. The AAAP research priorities of 2022 has ranked investigative studies related to histomoniasis epidemiology and pathogenesis as a top five research priority in the turkey industry (7).
This case report details a field investigation of blackhead disease outbreak in a turkey flock. An in-depth investigation is recommended in field cases to clearly understand the disease. Sometimes the disease etiology may be masked by or combined with other factors exhibiting an exaggerated manifestation of the disease. The field investigation study is a valuable tool to understand complicating factors involved in this disease.
Case report
Case history
In Fall 2022, a blackhead disease outbreak was reported in two barns in a 9 week-old turkey flock (12,300 turkeys per barn) located in the Midwestern United States. Each house was placed with 12,300 poults and the quality of the poults was considered poor at the time of placement. Turkeys received anti-coccidial feed additive Monensin, a polyether ionophore product. A pest control program was implemented on the farm. Poults were directly placed in the house and no litter amendments were used. Clinical signs such as dullness, depression, yellow stained vent, and ruffled feathers were noticed during a farm investigation. Dead birds were necropsied and gross lesions were observed in the ceca and liver. A presumptive diagnosis of blackhead disease was made based on the gross lesions. Turkeys exhibiting clinical signs were euthanized, necropsied and samples were collected.
Culture
Small pieces of cecal samples were collected from the necropsied turkeys and transported in plug seal-capped T25 flasks with 10 mL modified Dwyer’s media (8) with
0.8% (w/v) rice powder, 0.35% (wt/vol) sodium bicarbonate (Sigma-Aldrich, St. Louis, MO), and 5% horse serum (HyClone, Logan, UT) in Medium 199 powder (Gibco, Grand Island, NY). The culture flasks were shipped in a warm insulated Styrofoam box. The culture flasks were incubated at 40 °C for 2 days.
Intestine samples
The intestine samples were collected in zip-lock bags and triple bagged along with ice packs. The intestine samples were shipped in a cold insulated box. The intestines were evaluated for gross lesions and mucosal scrapings were collected from the duodenum, ileum, and ceca and evaluated under the microscope.
DNA extraction and PCR
Figure 1 - Gross pathology in liver and ceca of 9-week-old turkeys in a blackhead disease outbreak.
DNA was extracted from the ceca using the DNeasy® Blood & Tissue Kit (Qiagen, Hilden, Germany) following the manufacturer’s instructions. Previously described primers were used to amplify partial 18S ribosomal RNA (rRNA) gene of H. meleagridis (9) and Heterakis gallinarum (10), and cytochrome c oxidase subunit I gene (COI) of Eimeria species using previously published primers (11) and in-house primers. All PCR reactions were performed using GoTaq® G2 Hot Start Green Master Mix (Promega, Madison, WI) and 5 µM of forward and reverse primers were used.
Gel electrophoresis and sequencing
A. Presence of numerous necrotic foci on the liver and yellow stained vent.
B. Presence of numerous necrotic foci and coalescing necrotic foci on the liver.
Results
Gross pathology
After PCR amplification, the amplicons (2 µl) were electrophoresed and visualized on E-GelTM EX Agarose Gels, 2% (Invitrogen, Carlsbad, CA) using the E-Gel Power Snap Electrophoresis Device (Invitrogen). E-Gel 1 Kb Plus DNA Ladder (Invitrogen) was used as a reference to determine the size of the amplicons. The amplicons were purified using QIAquick PCR Purification Kit (Qiagen) and submitted for sequencing (Eurofins, Louisville, KY).
Necropsied turkeys had characteristic lesions in the liver and ceca suggesting histomoniasis. Multifocal to coalescent necrotic foci with dark centers and defined white periphery were noticed in the livers (Figures 1A, B). Cecal wall was thickened, hyperemic, and serosa inflamed with numerous petechiae and cecal core was visible without dissecting the ceca (Figure 2A). Cecal mucosa was thickened, edematous, necrotic and had numerous petechiae with creamy yellowish cecal core (Figure 2B).
Culture
The culture flasks were observed periodically under the inverted microscope. After two days of incubation at 40 ˚C under anaerobic conditions, H. meleagridis was observed in microscopic evaluation of the cecal culture (Figure 3A,
▲ Figure 2 - Gross pathology lesions in the ceca of 9-week-old turkeys in a blackhead disease outbreak.
A. Inflamed and congested ceca engorged with cecal core.
B. Inflamed and thickened cecal mucosa with numerous petechiae. Ceca engorged with creamy caseous core formed by feces and necrotic debris.
▲
▲ Figure 3 A, B - Photomicrograph of the culture flasks examined under inverted microscope. Arrow marks: Histomonas meleagridis, arrow heads: rice crystals. Note: Only few histomonads and rice crystals were marked for identification purpose.
B). H. meleagridis had amoeboid/ pulsative movements as described earlier (3,12). In addition to H. meleagridis, prolific growth of unidentified bacterial population was also detected in the flask.
Intestinal samples
Intestinal samples received in cold Styrofoam boxes were examined and mucosal scrapings were collected from the ceca. Wet mount examination of the mucosal scrapings from the ceca revealed the presence of Eimeria oocysts (Figure 4A, B,C).
targeted against cytochrome c oxidase subunit I gene (COI) of Eimeria species, a positive band was noticed at 1340 bp (Figure 6).
Sequencing
The purified gel products were submitted for sequencing. The sequences were analyzed using the National Center for Biotechnology Information database (https://blast. ncbi.nlm.nih.gov/Blast.cgi). The gene targeted sequencing of the PCR product generated from PCR against 18S rRNA of H meleagridis clustered with genotype 1 H meleagridis isolates and was 95% identical to H. meleagridis isolate 11/6346 (GenBank accession no.: HG008087.1). The gene targeted sequencing of the PCR product generated from PCR against cytochrome c oxidase submit I gene (COI) of Eimeria species revealed that the field isolate was 99% identical to E meleagridis (GenBank accession no.: KJ608418.1).
▲ Figure 4 - Microscopic identification of Eimeria oocysts from cecal mucosal scrapings of 9-week-old turkeys
PCR and gel electrophoresis
With the primers targeted against 18S ribosomal RNA of H. meleagridis, a positive band was noticed in the gel at 550 bp (Figure 5). No band was noticed in the gel with the primers targeted against H. gallinarum. With the primers
Discussion
Based on the gross lesions in the liver and ceca during onsite field investigation, a presumptive diagnosis of blackhead disease was made. PCR and culture confirmed H. meleagridis infection. In addition, evaluation of mucosal scrapings revealed the presence of Eimeria oocysts and confirmed as E meleagridis by PCR.
▲ Figure 5 - Gel image of amplicon generated using specific primers targeted against 18S ribosomal RNA of Histomonas meleagridis. Lane 1: molecular size marker (1 Kb Plus DNA Ladder); Lane 2: ceca; Lane 3: negative control without DNA template; Lane 4: positive control (H. meleagridis).
In turkeys, bacterial diseases such as colibacillosis, avian pasteurellosis, avian mycobacteriosis, spotty liver disease, pullorum disease, fowl typhoid, and viral diseases such as inclusion body hepatitis, turkey viral hepatitis, avian leukosis, Marek’s disease, and parasitic diseases such as histomoniasis and tetratrichomoniasis, can induce lesions in the liver. Cecal lesions can be seen in bacterial diseases such as salmonellosis, and parasitic diseases such as tetratrichomoniasis and coccidiosis (E. adenoeides, E. gallopavonis, and E. meleagridis). Both liver and cecal lesions can be seen in salmonellosis, tetratrichomoniasis, and histomoniasis.
In the past, concurrent infection of histomoniasis has been reported in several cases. Concurrent infection with bacterial pathogens such as Escherichia coli (13), Salmonella typhimurium (13) and Brachyspira-like bacteria (14), viral pathogen such as Hemorrhagic enteritis virus (4), and parasitic pathogens such as Pentatrichomonas hominis (3) and Eimeria spp. (15) have been documented. In this case, concurrent infection of H meleagridis and E meleagridis was documented.
E meleagridis was first described by Tyzzer in 1927 (16). The first generation schizonts of E meleagridis occurs in the small intestine, while the other generations and gametogony occurs in the ceca (17,18). E meleagridis is considered a nonpathogenic strain (19). However, studies conducted by Matsler and Chapman, concluded that E meleagridis may cause reduction in weight gain and the pathogenicity classification of E. meleagridis should be reconsidered (18).
Regardless of the pathogenicity, the damage incurred
▲ Figure 6 - Gel image of amplicon generated using specific primers targeted against cytochrome c oxidase subunit I gene (COI) of Eimeria species. Histomonas meleagridis. Lane 1: molecular size marker (1 Kb Plus DNA Ladder); Lane 2: ceca; Lane 3: negative control without DNA template; Lane 4: positive control (Eimeria sp).
Several factors are associated with increased mortalities, including virulence of the isolate, age of the birds, season, immune status of the birds, and concurrent infections
in the cecal epithelium during E. meleagridis replication cannot be ignored. Compromised cecal epithelium provides an unchallenging entry site for H. meleagridis to invade the ceca (3,4). Synergistic and exaggerated damage may be noticed in H meleagridis and concurrent infections with other pathogens. The interaction of H meleagridis with other pathogens needs to be investigated in detail for a better understanding of the disease.
With the unavailability of commercial vaccines and prophylactic/therapeutic measures, understanding the interaction of H. meleagridis with other pathogens helps in implementing proactive measures to minimize the risk of complicating/ aggravating factors.
References
1. Cushman S. The production of turkeys. In: Bull. 25, Agricultural Experiment Station. Kingston: (RI): Rhode Island College of Agriculture and Mechanical Arts; p. 89–123; 1893.
2. Hess M, McDougald LR. Histomoniasis. In: Swayne D, Boulianne M, Logue C, McDougald
L, Nair V, Suarez D, deWit S, Grimes T, Johnson D, Kromm M, et al., editors. Diseases of poultry. 14th ed. Ames (IA): Wiley-Blackwell. p. 1223–1230; 2020.
3. Durairaj V, Barber E, Clark S, Vander Veen R. Concurrent infection of Histomonas meleagridis and Pentatrichomonas hominis in a blackhead disease outbreak in turkeys. Avian Dis. 67:124–129; 2023.
4. Durairaj V, Nezworski J, Drozd M, Clark S, Veen RV. Concurrent Histomonas meleagridis and Hemorrhagic Enteritis Virus Infection in a Turkey Flock with Recurrent
History of Blackhead Disease. Avian Dis.56-64; 2024.
5. Durairaj V, Carriere R, Drozd M, Lin G, Keyser K De, Vander Veen R. The impact of histomoniasis in organic turkeys. Poultry World. Vol 40. No. 2: 20-23. 2024.
6. Clark, S., and L. Frobel. Current health and industry issues facing the US turkey industry. Proceedings of the 126th Annual Meeting of the United States Animal Health Association, Minneapolis, MN. p. 193–198; 2022.
7. American Association of Avian Pathologists. 2022 Research Priorities of the American Association of Avian Pathologists. [modified 2022 Oct 10; accessed 2023 Mar 29]. https://aaap. memberclicks.net/assets/Committees/Research_Priorities/ Research%20Priorities%202022.pdf; 2022.
9. Bilic I, Jaskulska B, Souillard R, Liebhart D, Hess M. Multi-locus typing of Histomonas meleagridis isolates demonstrates the existence of two different genotypes. PLOS ONE 9:e92438; 2014.
10. Cupo KL, Beckstead RB. PCR detection of Heterakis gallinarum in environmental samples. Vet Parasitol. 271:1–6; 2019.
11. Hafeez MA, Shivaramaiah S, Dorsey KM, Ogedengbe ME, El-Sherry S, Whale J, Cobean J, Barta JR. Simultaneous identification and DNA barcoding of six Eimeria species infecting turkeys using PCR primers targeting the mitochondrial cytochrome c oxidase subunit
I (mtCOI) locus. Parasitol Res. 2015 May;114(5):1761-8.
12. Tyzzer EE. The flagellate character and reclassification of the parasite producing ‘‘blackhead’’ in turkeys: Histomonas (gen. nov.) meleagridis (Smith). J Parasitol. 6:124–131; 1920.
13. Ganapathy K, Salamat MH, Lee CC, Johara MY. Concurrent occurrence of salmonellosis, colibaccillosis and histomoniasis in a broiler flock fed with antibiotic-free commercial feed. Avian Pathol. 29:639–642; 2000.
14. Esquenet C, De Herdt P, De Bosschere H, Ronsmans S, Ducatelle R, Van Erum J. An outbreak of histomoniasis in free-range layer hens. Avian Pathol. 32:305–308; 2003.
15. Chadwick E, Beckstead R. Two blackhead disease outbreaks in commercial turkey flocks were potentially exacerbated by poor poult quality and coccidiosis. Avian Dis. 64:522–524; 2020.
16. Tyzzer, E. E. Species and strains of coccidia in poultry. J. Parasitol. 13:215. 1927.
17. Clarkson MJ. The life history and pathogenicity of Eimeria meleagridis Tyzzer, 1927, in the turkey poult. Parasitology. 1959 Nov;49:519-28.
18. Matsler PL, Chapman HD. Characterization of a strain of Eimeria meleagridis from the turkey. Avian Dis. 2006 Dec;50(4):599-604.
19. Lund, E.E, & Farr, M.M. (1965). Coccidiosis of the turkey. In H.E. Biester & L.H. Schwarte (Eds.), Diseases of Poultry, 5th ed., (pp. 1088-1093). Ames, IA: Iowa State University Press.
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SELF-DOSY THE AUTOMATIC FEED PAN FOR COCKS
Sturdy, easy to manage and designed for aggressive birds.
Simple washing of any inner and outer component of the feed pan. It works with common flex auger systems.
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Example : 80 kg of feed must be distributed throughout one line with 50 pans
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Adjust the feed volume at 1,6 kg with the centralized winch
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The automatic opening is used to drop simultaneously the feed in all the pans
Picasiette is a manual feeder designed to ensure optimal feed hygiene and distribution. Its conical container ensures a gradual flow of feed onto a base plate, minimising waste. A protective lid keeps the feed clean, while the optional grid at the base separates the feeding area from the ground, reducing contamination. Compact, efficient and suitable for chicks, the Picasiette is the ideal solution for poultry care in the early stages of life.
