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EDITORIAL
➤ Marianna Caterino
As of summer 2025, the global poultry supply chain remains impacted by health-related challenges, while simultaneously experiencing substantial transformation.
The contributions in this issue explore ongoing epidemics alongside strategies for adaptation and revitalization, including vaccines, bio-security measures, advanced incubation technologies, extended laying cycles, and natural blends to promote animal welfare.
In the background, complex global dynamics are unfolding: some markets are reopening – such as the UK market for vaccinated French ducks – others are experiencing rapid growth, like Mongolia, while the European Union continues to navigate the delicate balance between health, production, and regulatory demands.
The result is a sector striving to balance efficiency with responsibility, integrating new technical knowledge, prioritizing animal welfare, and cultivating the foresight needed to address current and future challenges effectively.
JULY / AUGUST 2025
4 10 12 16 20 28
REPORTAGE
Carmistin unveils one of Europe’s most advanced poultry processing facilities
FIELD CASE
Mongolia moves fast: big expansions ahead
FOCUS
Balancing production efficiency and welfare
MARKETING
Fourth AI epidemic in the USA in the past decade - The epidemic in winter 2024/2025
TECH COLUMN
The effect of hot and cold hatcher temperature profiles on hatchability and chick quality
MANAGEMENT
A comparison of hen performance during an extended laying cycle based on hen body weight
NUTRITION
Incorporating an essential oil and saponin blend as part of an effective coccidiosis management program
VETERINARY
2024 avian metapneumovirus outbreak in the United States
MARKET GUIDE
UPCOMING EVENTS
INTERNET GUIDE
SPACE 2025, AT THE HEART OF ANIMAL FARMING COMMUNITY
SPACE 2025 will take place from Tuesday 16 September to Thursday 18 September at the Rennes Exhibition Centre. Following the tremendous success of SPACE 2024, this 39th edition also promises to be exceptional. More than 1,200 exhibitors and 100,000 visitors from 120 countries will once again gather in the heart of Western France at the start of the agricultural season.
The current geopolitical context is having a major impact on global agricultural and food balance. In this rapidly evolving environment, farmers continue to bear the responsibility of addressing not only food-related challenges, but also environmental, social, and energy issues. Solving this complex equation requires ever-greater professionalism, appropriate tools, and an openness to the world. SPACE stands as a forward-looking professional exhibition for all sectors of animal farming, offering participants tailored solutions to meet the evolving needs of farmers around the world. For its 39th edition, SPACE will shine a spotlight on artificial intelligence in support of farmers, aiming to improve precision, performance, working comfort, and animal health management. SPACE is also the must-attend event where exhibitors showcase their innovations and apply for the Innov’Space label. This innovation and progress label will celebrate its 30th anniversary in 2025.
Top-level participation from exhibitors
The number of registrations is very high, even surpassing that of 2024 at the same point in time. SPACE will once again offer an exceptionally comprehensive showcase for all professionals in mixed farming and animal farming. Nearly 1,100 companies are already registered (1,093), including 311 international exhibitors. Among them, 195 are first-time participants.
SPACE remains the only exhibition to provide such an outstanding offering across all animal farming sectors: dairy and beef cattle, pig, poultry, goats, sheep, and aquaculture.
Visitors from around the world gather at the Animal Farming Community event
International outreach is part of SPACE’s DNA, and its global recognition is the clearest proof. By embracing the “European Crossroads” dimension in the meaning of the SPACE acronym, the exhibition has consistently upheld and developed this positioning. Since its creation, SPACE has made continuous efforts to support exhibitors in developing and expanding their export markets. A dynamic international promotional campaign is in full
swing to attract a high-level global audience to Rennes this September. New in 2025: to reinforce SPACE’s technical and scientific contribution to African countries (32 African countries were represented at SPACE last year), a training course dedicated to poultry farming in hot climates is being relaunched in partnership with INNÔZH, a technopole and technical centre specialised in innovation, consulting, and training for animal farming sectors.
Happy 30th Anniversary Innov’Space
With nearly 3,500 entries submitted, 1,437 innovations awarded, and over 700 award-winning exhibitors, Innov’Space has been a key driver of innovation in animal farming for the past 30 years. This prestigious label is a powerful mark of recognition for companies’ expertise –and a major boost to their communication and marketing efforts. To celebrate its 30th anniversary, Innov’Space will feature special events and shine a spotlight on the most awarded winners since its creation.
Artificial intelligence in support of farmers at the Espace for the Future
Decision-making and predictive artificial intelligence are currently the most widespread and valued forms of
AI globally, accounting for 90% of ongoing projects. By analysing quantitative and visual data, these tools provide essential insights that help anticipate decisions and optimise processes. They are particularly effective in risk management, helping to address climate-related, health, and other operational risks. AI also serves as a catalyst for attractiveness and sustainability across all sectors. It is within this context that SPACE and the Brittany Chamber of Agriculture have chosen to spotlight this theme in the Espace for the Future.
Conferences
The conference programme is once again very extensive this year. The number and diversity of topics covered make SPACE a truly unique meeting and exchange platform in the field of animal farming. Investing in new technologies, artificial intelligence serving people and professions, the evolution of international trade rules, ethology and advisory services to support farmers, reconciling milking robots and agroecology, etc. All these topics — and many more — will be featured in the programme of over one hundred conferences and roundtable discussions taking place over the three days of the Exhibition.
www.space.fr/en/home
BRITISH MARKET REOPENS TO VACCINATED FRENCH DUCKS
British authorities have announced that, starting 22 May 2025, the United Kingdom will resume imports of duck meat from France, including products from ducks vaccinated against highly pathogenic avian influenza (HPAI).
The British market had been closed to these exports since March 2024, following the launch of France’s mandatory HPAI vaccination program for ducks in October 2023. At the time, UK authorities raised concerns over the effectiveness of France’s post-vaccination surveillance and monitoring systems.
In response, the Directorate General for Food (DGAL) of the French Ministry of Agriculture and Food Sovereignty, in coordination with FranceAgriMer, the French Embassy in London, and representatives of the duck industry, carried out an extensive diplomatic and technical effort to address the UK’s concerns.
A decisive step in this process was the audit conducted by the UK Office for the Assurance of Sanitary and Phytosanitary Trade (UK SPS Office), which took place in France from 2 to 6 December 2024. The audit evaluated both passive and active surveillance components of the vaccination strategy, with a particular focus on implementation in the field. The auditors concluded that
the French vaccination program is robust and effectively implemented, supported by a well-structured surveillance system. The positive outcome of the audit played a key role in the UK’s decision to lift the embargo. This development marks a major success in health diplomacy and highlights the importance of maintaining strict standards in future vaccination and monitoring campaigns. Continued confidence in the integrity of the French program will be critical in encouraging other third countries to lift their own trade restrictions on French poultry and related products.
Annie Genevard, French Minister of Agriculture and Food Sovereignty, commented: “Two years after the launch of our vaccination campaign – unprecedented in its scale globally – I am pleased with the trust we have maintained with our trade partners, and I want to highlight the dedication of all those who contributed to this achievement.”
BRAZIL OPENS DEBATE ON BIRD FLU VACCINATION
Brazilian Agriculture Minister Carlos Favaro in June welcomed the opportunity to debate vaccination of poultry against bird flu following the country's first confirmed outbreak on a commercial chicken breeding farm last month.
Speaking in Paris at the World Organization for Animal Health, Favaro said Brazil would be prepared to host a global conference on animal health in 2026, saying it would be the ideal venue for such a discussion to take place.
The potential use of vaccines against highly pathogenic avian influenza could restrict access to markets for Brazil, the world's largest chicken exporter. But Favaro called for a discussion involving sellers and buyers to waive any restrictions in case vaccination is adopted, as Brazil is already
facing bird flu-related trade bans. Favaro also defended a regionalization model under which trade bans would only apply to specific locations affected by outbreaks of highly contagious diseases such as bird flu or Newcastle disease. Brazil in June 2025 received a formal certification as a country free of foot-and-mouth disease without vaccination, which in theory could give Brazilian beef access to stricter markets, like Japan.
Source: Reuters
SOUTH AFRICA BEGINS MASS POULTRY VACCINATION AGAINST HPAI
The Minister of Agriculture, John Steenhuisen, has announced the initiation of South Africa’s first mass vaccination campaign against avian influenza in poultry, aimed at safeguarding the national flock from the ongoing threat of the disease.
A designated vaccination team, comprising poultry veterinary specialists from the University of Pretoria in collaboration with the Agricultural Research Council, has received a prioritized list of poultry farms from industry stakeholders. The team is currently focusing on highrisk zones and commercial operations to contain viral transmission and reduce the need for further depopulation measures.
As of early 2025, three vaccines targeting highly pathogenic avian influenza (HPAI) H5 have been officially registered for use in South African poultry under Act 36 and approved by the Department of Agriculture, Land Reform and Rural Development (DALRRD):
• Vectormune® H5 (Ceva Santé Animale): A recombinant vector vaccine utilizing turkey herpesvirus (HVT) as a vector to express the H5 antigen. It is administered to day-old chicks, either in ovo or at hatch. Vectormune® H5 was among the first H5 vaccines registered in South Africa (2023).
• Boehringer Ingelheim “B.E.S.T” H5 Vaccine: An inactivated, oil-adjuvanted H5 avian influenza vaccine coformulated with Newcastle Disease virus (LaSota strain), produced using Baculovirus Expressed System Technology. It is administered by injection and intended for use as a booster in older birds. This vaccine was fast-tracked for registration and approved during the 2023–2024 period.
• Zoetis HPAI H5N1 Vaccine (Inactivated): An inactivated vaccine based on reverse genetics, developed to match contemporary H5Nx Goose/Guangdong lineage (clade 2.3.4.4) strains implicated in recent South African outbreaks. It is registered and approved for poultry use.
These vaccine registrations represent a significant milestone in South Africa’s strategic approach to mitigating the impact of HPAI outbreaks and advancing long-term biosecurity in the poultry sector.
Source: PoultryMed
NIKOLAUS KRIZ IS EFSA'S NEW EXECUTIVE DIRECTOR
The European Food Safety Authority’s Management Board has nominated Dr. Nikolaus Kriz as EFSA’s next Executive Director for a five-year term from September 2025.
“I am very pleased to announce that today the Board voted to nominate Dr. Nikolaus Kriz as EFSA's next Executive Director” said Aivars Bērziņš, Chair of EFSA’s Management Board. “With his significant leadership experience in regulatory settings and deep scientific expertise, we are confident he will further strengthen EFSA’s role as the EU reference point for independent food safety risk assessment. On behalf of the Board, I also take the opportunity to extend our sincere gratitude to Dr. Bernhard Url for his outstanding leadership as EFSA’s Executive Director over the past eleven years”.
Nikolaus Kriz joined EFSA in 2017 and is currently Head of the Authority’s Risk Assessment Services (ENABLE) Department. A veterinary surgeon by training, he held various roles at the European Medicines Agency (EMA)
in veterinary and public health risk assessment prior to joining EFSA. After the vote of the Management Board was announced, Dr. Nikolaus Kriz commented: “I am honoured and grateful to be nominated to lead EFSA. Together with its exceptional staff and experts, I look forward to guiding the organisation as we continue our vital mission to protect the health of EU citizens, animals, plants and the environment”.
The final part of the selection procedure will see Dr. Kriz deliver a statement before the European Parliament’s Committee on the Environment, Climate and Food Safety (ENVI) and answer questions from its Members. The session is expected to take place on 14 July.
Source: EFSA
CARMISTIN
UNVEILS ONE OF EUROPE’S MOST ADVANCED POULTRY PROCESSING FACILITIES
Romanian agrifood giant Carmistin The Food Company has inaugurated a state-of-the-art poultry processing facility in Frâncești, Vâlcea County –now the most technologically advanced plant of its kind in the region, and one of the largest in the European Union.
With an investment exceeding €80 million, the facility marks a significant milestone for Romania’s poultry sector, positioning Carmistin as the country’s top-performing poultry meat producer. With this project, developed on a 6-hectare plot and covering a total built area of 25,000 square meters, the Carmistin Group becomes the most high-performing poultry meat producer in Romania, with a production capacity of 120,000 tons of meat per year.
A benchmark in poultry innovation and efficiency
Representing a benchmark in innovation, architecture, and design in the food industry, the new plant was designed to meet top technological and operational standards, responding to the demanding requirements of modern trade.
The equipment, most of which operates with the help of artificial intelligence, was selected for enhanced efficiency and food safety, as well as optimal process streamlining. For example, the ATLAS system for poultry transport from farms, recently launched globally, is considered the most advanced in terms of animal welfare – a particularly important aspect for Carmistin The Food Company and its premium brand, La Provincia.
The Impaq software provides data on the operation of the primary processing section, enabling real-time analysis of equipment efficiency and reducing downtime. The Iris system automatically classifies carcasses by quality grade, optimizing production and identifying causes of downgrades. Additionally, an integrated set of five calibration robots ensures optimal product weight distribution.
From this new production unit, the company already delivers La Provincia-branded products to the domestic market, as well as export goods to over 30 countries, ranging from fresh meat to a wide variety of cuts tailored to meet diverse consumer demands and preferences.
The Frâncești project was designed and built on the model of a fully integrated food supply chain – a concept promoted by the Carmistin Group for over two decades – which, in harmony with global trends, now translates into innovation, freshness, and a responsible, sustainable approach to production and agriculture. The company has thus strengthened its entire value chain, from agricultural inputs (grains, seeds, feed) and hatcheries to breeding farms, processing, packaging, logistics, distribution, and its own retail network developed nationwide.
In addition to increasing production capacity, the new factory is also generating a strong socio-economic impact in the area, currently operating with a team of nearly 1,000 people, including 600 newly hired employees recruited through an intensive campaign conducted in recent months.
The execution of the Frâncești project was carried out between 2022 and 2025 by an in-house team of about 10 people, supported by dozens of specialists and external collaborators from around the world.
“Such an investment is proof that innovation and state-ofthe-art technology can be perfectly harmonized with the responsible development of a large-scale local business”, said Justin Paraschiv, Founder and President of Carmistin The Food Company. “With the Frâncești project, we aim to redefine not only the standards in local food production but also how the food industry is perceived. For us, the Carmistin The Food Company team, and especially for the extraordinary people who contributed to its realization, this jewel-project was and will always remain a unique experience – human, professional, and personal. I thank all my colleagues for understanding that at the core of all our efforts lies the constant commitment to providing food to the market at the highest standards of quality, trust, and safety.”
The equipment, most of which operates with the help of artificial intelligence, was selected for enhanced efficiency and food safety, as well as optimal process streamlining
According to the latest RaboResearch analysis, global poultry meat consumption continues to rise in 2025, with an estimated annual growth rate of 2.5-3%, due to poultry’s competitive position compared to other proteins. Europe, including Romania, is one of the regions with the strongest demand, driven by stable prices, consumer preference for responsibly produced goods, and the availability of quality local products.
In Romania, poultry meat consumption has seen steady growth in recent years, reinforcing its position as the primary source of animal protein. This trend is supported by both economic dynamics – which keep poultry meat an affordable option – and changing consumer behavior, increasingly oriented toward healthy, trustworthy, locally produced food. Poultry remains a top favorite also due to its culinary versatility and dietary value.
Carmistin The Food Company is currently among the leading food producers in Romania and ranks first among national meat producers. The group includes over 50 companies active in poultry and egg production, pig and cattle farming, as well as grain production, utilizing over 8,000 hectares of farmland. These resources ensure both operational independence and consistent product quality throughout the Group’s companies.
MONGOLIA MOVES FAST: BIG EXPANSIONS AHEAD
In nomadic Mongolia, poultry farms have seen a boom over the past years. Industry players anticipate more growth in the near future, with Government support.
➤ Mainbayar Badarch, Market analyst
Mongolia is home to the pastoral livestock industry, having 58 million head of livestock, mostly sheep and goats. However, over the last decade, the country has increasingly shifted to the poultry industry. The root causes are its growing economy based on mineral resources and food choices diversification.
Its first poultry farm was established in 1963 with the support of the former Soviet Union. When socialism collapsed in 1990, Mongolia was producing 20 million eggs annually. Today, the nation consumes over 500 million eggs annually and local producers provide 300 million eggs of them. Currently, over 20 poultry companies are operating in the country.
How did national big poultry farms emerge? The Government’s support was invaluable. It provided VAT exemptions for poultry farming and feed mill equipment, as well as low-interest loans under the National Movement for “Food Supply and Security”, initiated by the Mongolian President in 2022. Over MNT40 billion (US$12 million) of low-interest loans were provided to 7 poultry companies. As a result, according to the National Statistics Committee, the total number of egg-laying hens increased from 822,500 in 2022 to 1,554,000 in 2024, an increase of 90%.
Leading players
Tumen Shuvuut JSC started its operation in 2004. At present, they produce 150 million eggs per year, having 800,000 layers and using Western technologies such as Sanovo. In 2019, the company became a pioneer in the agricultural industry by launching an IPO at the Mongolian Stock Exchange. As a result, they raised US$3.8 million for farm expansions.
Last year, the company earned US$24.5 million, with a net profit of US$4.4 million and a profit margin of 18%. The
company operates with an ROA of 15% and ROE of 25%. In early 2024, construction work began on the new Tumen Shuvuut-3 farm (Phase-3). The farm will have 8 laying houses for 400,000 hens and 2 houses for 100,000 chicks. With this new extension, Tumen Shuvuut will increase its laying hen population to 1 million and its chick population to 300,000, producing 230-250 million eggs annually and supplying 50% of the domestic egg consumption alone. This will enable them to meet 90% of Mongolia’s domestic consumption, together with other domestic producers.
For the Tumen Shuvuut-3 project, the company received an investment loan of US$4.4 million from Golomt Bank for 60 months, with an annual interest rate of 6%, under the preferential loan terms provided by the Ministry of Agriculture.
In addition, Tumen Shuvuut is developing an ECO production complex including a livestock and poultry feed mill, an internal testing laboratory meeting high standards, a liquid egg factory (mainly for bakery products), and a compost fertiliser factory for recycling eggshells and excrement.
The second market player is NVTS LLC, established in 1998. They are recognised by their Bayan Egg brand and currently operate with 1 million layers. They installed the German-made Big Dutchman system and received The Golden Egg Award from the World Egg Commission. Homegrown wheat accounts for 60-70% of the feed and it serves as a tastemaker. In the near future, NVTS plans to increase the number of its layers to 1.5 million.
The third company is Neon Shell LLC. It works with 130,000 chickens and fully automated equipment, supplying 11% of the domestic egg market. In 2008, they purchased the latest advanced equipment from Tecno and Salmet and brought Italian and German experts to Mongolia to install and test equipment. Other international brands such as the Nuovo egg stamping system are also being used. The farm feeds chickens by TMS in accordance with Dutch standards.
The company is currently doing a feasibility study for a mixing plant project to prepare complete chicken feed to
further increase the quality and efficiency of egg production. They plan to increase the number of chickens to 200,000. According to Mrs. Dalantai Tudev, Executive Director of Neon Shell, “European poultry equipment has the best quality. It can last for up to 25 years while Chinese-made equipment may last for 15 years. We tried to import poultry equipment from Europe for our latest farm expansion during COVID-19. However, the transport cost was too high and we were forced to import equipment from China built to American standards.”
The latest industry player is Ueg Undug LLC. It owns 60,000 layers along with its own feed plant and has the ambition to reach 1 million layers within 5 years. The company is constructing a new farm for 200,000 layers. Given that Mongolia is the 17th largest country in the world in terms of territory, several small-sized poultry farms have been established in remote provinces, which are based near rural customers and deliver fresh eggs.
■ Table 1 - Growth in the population of laying hens (in thousand heads) between 2014 and 2024
Year Layers (by thousand heads)
2014 651,39
2015 552,40
2016 577,35
2017 443,51
2018 672,32
2019 675,86
2020 811,16
2021 945,92
2022 822,48
2023 1266,46
2024 1553,87
Source: NSC
Broilers
Mongolia imports more than 22,000 tonnes of chicken meat from abroad annually for US$5060 million, and statistics show consumption is growing by 20% every year. The leading Mongolian broiler breeder is Ajigana LLC which produces more than 1,000 tonnes per year, covering 5% of domestic chicken consumption. In 2013, Ajigana established Mongolia’s first broiler farming complex called Orgio Chicken with Western equipment such as Petersime. The facility can process approximately 1 million chickens per year by breeding Ross-308 meatoriented broiler chickens. The complex consists of 6 small plants. They import flocks from South Korea on a quarterly basis, as transportation
from Europe takes significantly longer. Ajigana started the business by acquiring the Israeli poultry farm’s know-how and adopting McKinsey’s 7S Frameworks for the farm. Given that Mongolia’s winter is harsh, they operate a big steam boiler to provide heat and moisture, albeit at a high cost.
Orgio chicken farm received a loan of US$2.5 million under Food Supply and Security to build a new warehouse, modernise its parent flock, and increase its production capacity. It has also expanded its feed factory, installed a new incubator, and benefited from customs duty exemption. In the future, the company aims to automate its slaughterhouse, introduce an automatic management and control system, increase the capacity of its parent flock by 50%, collaborate with cooperatives and chicken enterprises, and supply 20% of local chicken meat consumption. With other local producers, they may supply 50% of the local consumption in the near future.
The State Secretary of the Ministry of Agriculture Mr. Jambaltseren Tumur-Uya noted that by providing all kinds of support to enterprises under the Movement Food Supply and Security, domestic consumption of chicken meat will be supplied by local producers within 5-7 years.
Eurasian Economic Union Free Trade Agreement
On June 27, 2025, the Interim Trade Agreement between Mongolia and the Eurasian Economic Union (which includes Russia) was officially signed in Minsk, the capital of Belarus. The agreement is set for a three-year period and will be submitted to the Mongolian Parliament for ratification. One of the key points concerns egg imports, which currently carry a 15% import tax. According to the agreement, this rate will be reduced to 7.5% with a quota. Most poultry farmers have been voicing to protect the national poultry industry from Russian low-cost egg suppliers. Mr. Erkhembayar Lombo, Board Director of Tumen Shuvuut stated: “the Government plans to reduce customs duties by 50% on 90 million eggs imported from Russia. Our association has requested not to include eggs in the 367 goods exempt from duty. If this is not possible, the import volume should at least be decreased from 90 million to 30 million. However, the Government remains adamant.” According to the National Statistics Committee, in 2023, Mongolia imported 183 million eggs (worth US$14.5 million) from Russia. Last year, it dropped significantly to 98 million eggs, down by 86%. Mr. Erkhembayar Lombo further commented on the business environment in Russia and Mongolia as of January 2025:
1. Grain and feed raw materials in Russia are 30-40% cheaper than in Mongolia.
2. 1kW of energy in Mongolia is 3-5 times more expensive than in Russia.
3. Diesel fuel in Russia is US$0.6 per litre, in Mongolia, it is US$1.1 or 90% more expensive.
When socialism collapsed in 1990, Mongolia was producing 20 million eggs annually. Today, the nation consumes over 500 million eggs annually and local producers provide 300 million eggs of them
4. In Russia, the corporate profit tax in the agricultural sector is “0”, while in Mongolia it ranges from 10 to 25%.
5. In Russia, VAT is 5% and 100% is refunded for exports. VAT is 10% in Mongolia.
6. The price of agricultural machinery, equipment, and spare parts is 45-90% more expensive in Mongolia.
7. Products for increasing and protecting agricultural yields, such as fertilisers and herbicides, are 30-150% more expensive in Mongolia.
8. The loan interest rate for the agricultural sector in Russia is 5-7% per year, compared to 19% in Mongolia.
9. In Russia, US$88,200 are provided to citizens as non-repayable grants starting small- and medium-sized businesses in the agricultural sector (eggs, meat, and milk).
10. In 2024, Russia provided US$14.9 billion as state support to the agricultural sector and plans to continue providing further support.
11. The heat balance of the Russian agricultural region is 20-30% higher than that of Mongolia, and the thickness of the humus soil is 15-40% higher.
Two countries with such radically different environmental and economic conditions cannot be compared. If Russia, which produces food at such a low cost, is allowed to export eggs at reduced customs duties, the Mongolian poultry industry could face immediately collapse, with recovery possibly taking over 20 years.
In a nutshell
The current egg consumption in Mongolia is 3 times below the world average, suggesting strong potential for future growth, as more Mongolians are expected to incorporate eggs into their daily consumption. By 2030, Mongolia could supply 100% of domestic egg demand. In terms of broilers, the situation is different, with the main thing being the cost factor. China supplies chicken meat to Mongolia at a very low cost and therefore, local broiler breeders need to work to improve cost efficiency – a process that will take time before gaining a competitive advantage.
BALANCING PRODUCTION EFFICIENCY AND WELFARE
Early poultry selection programs for feed efficiency and production traits alone have been proven successful at developing commercial lines of highly prolific layers and fast-growing broilers. Yet, such genetic potential for only desirable production traits often falls below actual on-farm flock performance since commercial conditions can be stressful and challenging, potentially taking a toll on birds’ physical and mental health.
➤ Aitor Arrazola, Research biologist, Ph.D. in Animal Behaviour & Welfare
Pushing toward resilience
Further improvements in feed efficiency, from nutrient intake to utilization, are still a must nowadays because of the never-ending worldwide pressure to optimize resource utilization for sustainable production. And, to attain such desirable production outcomes, birds need to stay healthy (physically and mentally) until the end of their production cycle. Although some producers can already get closer to performance objectives described by breeding companies, the reality for most of them is quite different for different reasons.
Firstly, commercial conditions can be undoubtedly challenging and stressful for birds and each production system faces its own struggles. For example, cage systems for laying hens offer limited opportunities to engage in species-specific behaviours and physical exercise which can result in feather pecking problems while managing birds in multitier systems require efforts to prevent bone fractures and deviations.
Secondly, and generally speaking, managing barns housing large volumes of birds at high stocking densities can become a struggle from a biosecurity standpoint as preventing disease spread and containing outbreaks is tough. Thirdly, breeding facilities where pedigree and grandparent lines are housed poorly reflect housing conditions in commercial barns due to high biosecurity protocols and standards in place, high-tech facilities, specialized management to phenotype performance throughout lifetime, and relatively small flock size. All of these create a mismatch between expected objectives vs observed performance under commercial conditions. Then, the closer commercial conditions resemble those in breeding facilities, the lower
The globalization of the poultry sector might drive the mindset that one chicken breed can be employed in any production system across countries and achieve optimal performance in all of them, which is far from reality
the gap between the actual flock performance on-farm and the target.
The stressful nature of commercial conditions is unavoidable, just like the potential biosecurity risks of disease outbreak or pathogen exposure. So, birds must be competent at coping successfully with potential stressors and biological agents which can threaten their (physical and mental) well-being and performance. This ability to remain steady and unaffected by external threats is socalled resilience, and selecting for this trait can benefit producers that struggle at keeping indoor conditions well-balanced in terms of within comfort zone, stressfree, and secure from physical and biological hazards. When it comes to body’s defenses against diseases, birds must develop a strong, immune response to perform well under commercial conditions, particularly if there is room to improve barn cleanliness standards. Including such immunological traits in their breeding schemes can help develop more resilient poultry lines to local conditions and lower the severity of biosecurity breaches. Similarly, including stress markers into breeding programs (i.e., number of fault bars in feathers) can help identify how birds cope with environmental stress and select those with proven coping skills. Thus, adding metrics related to how well birds can cope with commercial conditions in breeding selection schemes, on top of performance and health outcomes, can help develop more resilient poultry breeds and tackle current gap between genetic potential and on-farm performance.
Seeking adaptability
The globalization of the poultry sector might drive the mindset that one chicken breed can be employed in any production system across countries and achieve optimal performance in all of them, which is far from reality. On the other side, thinking about how well adapted poultry breeds are to conventional production systems can benefit the poultry industry become more sustainable. In this context, the genotype-environment interaction gains weight either 1) adjusting poultry houses and management to the needs of highly prolific breeds or 2) selecting the most productive birds that suit the best to local conditions and production system (e.g., aviaries or furnished cages). This perspective can allow producers to choose the genetic background that fits nicely to their needs and reach reliable performance outcomes. Also, from a welfare standpoint, this approach can mitigate the number of losses and birds left behind by the end of the production cycle due to enhanced fitness and competitiveness of each bird. Tunning this interaction between genotype and environment also enables breeding companies to cover a wide range of market needs and niches, from modern breeds to more traditional and heritage lines, and deliver specific solutions to producers’ needs.
Similarly, and beside making commercially available this genetic variability, producers must also be aware of what birds suit the best to their management and care instead of seeking highly prolific lines since they can achieve overall greater revenue choosing the right bird for them. Research in this field has noted that poultry breeds respond differently to husbandry systems but also to flock management. For example, management practices such as easing early feeding and hatchery-to-brooder transition, mitigating lifetime distress, maintaining a healthy body conformation uniformly, photo-stimulating at the right time, and upholding solid biosecurity standards are key determinants to achieve full genetic potential of highly prolific lines. However, putting this knowledge consistently into practice daily is demanding, and for producers who may struggle with this, alternative easy-going and resilient breeds can be a better fit for them to attain greater performance and well-being.
FOURTH AI EPIDEMIC IN THE USA IN THE PAST DECADE - THE EPIDEMIC IN WINTER 2024/2025
In the last ten years, the poultry industry in the USA has been hit by four devastating outbreaks of avian influenza. This article focuses on the most recent epidemic during the winter of 2024/2025, highlighting the high regional concentration of outbreaks and the resulting economic and production losses.
➤ Hans-Wilhelm Windhorst
Professor Emeritus at the University of Vechta, Germany
Between April 2015 and April 2025, the highly pathogenic AI virus (HPAI) was diagnosed on 933 farms. A total of 190.5 million poultry died due to virus infections or preventive culling. Of these, 150.6 million were laying hens and 24.6 million turkeys (Table 1).
■ Table 1 – HPAI outbreaks and animal losses in the USA between April 2015 and April 2025 (source: APHIS).
cases from the central Midwest to the South-Central states and another on the eastern side of the USA from New England to the South-East. It was not until mid-March 2025 that the number of infections fell significantly. The high animal losses in laying hens, which had a significant impact on the population’s egg supply and on egg prices, revived some issues that had already been the subject of very controversial discussions in 2022. One issue was the possibility of preventive vaccination and the other was how farms should be compensated from US Department of Agriculture (USDA) funds for animal losses due to infection or preventive culling. The pressure on the federal government to take action in these areas grew and led to reactions, which will be discussed in more detail towards the end of this article. Firstly, an overview of the course of the epidemic in 2024/25 will be given.
A remarkable timeline
While there were around seven years between the first two epidemics, the third and fourth followed less than one year apart. After the devastating economic consequences of 2022, it was hoped that a comparable epidemic would not be repeated so soon, but the new wave of outbreaks hit the poultry industry again in the winter months of 2023/24 shortly after the recovery from the Covid-19 epidemic. After a few months in the summer without AI cases, new outbreaks occurred in the Pacific states in October 2024, and from the end of November in the western Great Plains and the northern Midwest. Shortly after the turn to the year 2025, a new cluster formed with very high outbreak
Between October 15th, 2024 and April 14th, 2025, a total of 250 outbreaks of the HPAI virus in commercial farms occurred in 29 states. This revealed a remarkable spatial pattern. As Figure 1 shows, the epidemic began in the three Pacific states and Utah. Overall, large flocks of laying hens were involved. This was followed by 4 outbreaks in broiler farms in California. Numerous farms were affected here in the following weeks, with turkeys and broilers in particular being infected. A total of 62 outbreaks were registered in California by the beginning of February 2025 (Cluster I). From the end of November 2024, a new cluster (II) formed in the northern Midwest as far south as Oklahoma. Most cases were recorded in South Dakota. The two Dakotas
▲ Figure 1 - The spatiotemporal diffusion of the HPAI virus in the USA between October 2024 and April 2025 and the formation of clusters
and Minnesota had already suffered high losses in previous outbreaks, especially in turkey flocks. However, the total number of outbreaks in this cluster was lower than in 2022 and 2023/24.
Although some farms in the eastern Great Plains and the Midwest were also infected in the last two months of 2024, especially turkey farms and some layers and broiler flocks, a larger number of outbreaks did not occur until mid-January 2025. From then on, a new cluster (III) formed around the states of Ohio, Missouri and Indiana. From mid-March, the number of infections decreased significantly, but on April 14th, 2025 a large laying hen farm in Ohio was affected. It is worth noting that California (62) and Ohio (61) not only recorded an almost identical number of cases, but also roughly the same number of animal losses (Table 2). Almost parallel to the Midwest, a fourth cluster (IV), although less massive, developed on the east side of the USA between New York and Georgia, here, mainly broiler and duck farms were affected, as well as some turkey and layer farms.
Looking at the overall spatial pattern of the outbreaks, it is obvious that it reflects the three predominant flyways of wild birds. Infections started in the West (Pacific Flyway), followed by the western Great Plains states and the northern Midwest, then the central Midwest to the SouthCentral (Mississippi Flyway). The Atlantic coastal states were less affected overall (Atlantic Flyway). Here, mainly broiler farms were infected, which is not surprising given the geographical pattern of broiler production in the USA.
High regional concentration of outbreaks and losses
Figures 2 and 3 show the ten states with the highest number of infected farms and animal losses. Figure 2 reveals that out of a total of 250 registered HPAI virus infections in commercial poultry flocks (excluding small flocks), California and Ohio alone accounted for 123 respectively 49.2%. The regional concentration of losses was similar. Again, California and Ohio accounted for 49.2% (Figure 3). The shares of the two states during the winter 2023/24 epidemic were similar at 49.0% (Windhorst 2024). The epidemic in 2022 differed significantly from the following two, as the northern Midwest was mainly affected and the regional concentration was significantly lower (Windhorst 2023).
Figure 4 shows that the number of outbreaks and the associated animal losses varied considerably over time. More than 20 infected farms were recorded in three weeks, while fewer than five were recorded in nine weeks. Weekly losses ranged from 15,000 to 8.4 million animals. In 16 weeks, more than 1 million animals fell victim to the virus or were culled as a preventive measure. On average, this was 2.5 million per week, causing major problems with the removal and disposal of the dead animals in
■ Table 2 – Share of the ten states with the highest animal losses caused by the HPAI outbreaks in the USA between October 2024 and April 2025 (source:: APHIS).
State Animal losses (1,000)
California
Ohio
Iowa
Indiana
Missouri
S.
Carolina
Pennsylvania
Utah
Arizona
Maryland
* sum does not add because of rounding
Share (%) in the total losses
▲ Figure 2 - Share of the ten states with the highest number of HPAI outbreaks in the USA between October 2024 and April 2025 (design A.S. Kauer based on APHIS data).
▲ Figure 3 - Share of the ten states with the highest animal losses caused by HPAI outbreaks in the USA between October 2024 and April 2025 (design A.S. Kauer based on APHIS data).
the counties where laying hen farms with several million birds were affected. Comparing the graph of outbreaks and the columns of animal losses, a certain correlation between the number of infected farms and animal losses can be seen. However, this is not a direct correlation as even a low number of outbreaks led to high losses when large laying hen farms were affected, as in weeks 42/2024 and 49/2024. The number of outbreaks of the HPAI virus in the epidemic analysed here, was 96 cases or 62.3% higher than in 2023/24, and the losses of 61.7 million birds were even 38.6 million or 167.1% higher. This is mainly due to the large laying hen farms affected, with up to 4 million
birds. Laying hen farms accounted for only 27.2% of the total outbreaks but 81.5% of the losses, while turkey farms accounted for 45.5% of the outbreaks but only 6.3% of the total losses. Broiler farms shared 16% in the outbreaks and 10.7% in the animals that died or were culled (Figure 5). These differences are reflected in the average size of the farms. Whereas laying hen farms had an average size of 806,000 places and broiler farms of 165,000, it was only 34,000 for turkeys. The distribution of cases by farm size class is shown in Table 3. The high economic losses that have occurred in farm complexes with several million laying hens on one site have led to a renewed discussion of whether these efficiency-oriented scales represent an undesirable development and whether housing facilities of this size should no longer be built1
The problem of high economic losses when very large
■ Table 3 – Distribution of the HPAI outbreaks in the USA between October 2024 and April 2025 by sizeclasses of the respective flocks (source: own calculations based on APHIS data).
▲ Figure 4 - HPAI outbreaks and related animal losses in the USA between October 2024 and April 2025 (design A.S. Kauer based on APHIS data).
■ Figure 5 - Animal losses caused by HPAI outbreaks in the USA between October 2024 and April 2025 by poultry species (design: A.S. Kauer, based on APHIS data).
flocks are infected can be documented by comparing the number of cases with the number of animals lost per week. These are compared in Figures 6a-c for laying hens, broilers and turkeys.
Figure 6a shows that the peaks for laying hens were recorded in weeks 42 and 49 in the last quarter of 2024 and in weeks 4 and 7 in the first two months of 2025. In both cases, farms with more than 1 million places were affected, in week 42 a farm with 1.8 million hens in Utah, in week 49 a farm with 1.7 million in California and a farm with more than 4 million hens in Iowa. In week 4, there were 4 facilities with 1.2 million to 1.8 million places each in Missouri and Ohio, and in week 7, 3 facilities in Indiana with over 1 million birds each.
The highest losses in broilers also occurred in very large flocks (Figure 6b). In week 44, three farms in California with more than 100,000 broilers each were infected, and in week 46, three farms with more than 200,000 birds each. In week 4/2025, it was again a large farm in California with 441,000 broilers. Apparently, the farms were not able to protect their flocks with a high level of biosecurity. One explanation for this could be the low number of cases on broiler farms in previous epidemics, which may have led to the assumption that broiler flocks are less susceptible to infection. Despite the smaller average size of turkey flocks
1 Doughman, E.: Stopping HPAI may require changes to poultry farming. https://www.wattagnet.com/poultry-meat/diseaseshealth/avian-influenza/news/15743723/rethinking-poultryfarms-to-combat-avian-flu.
■ Figure 6 A-C - The timeline of the HPAI-outbreaks in laying hen, broiler and turkey flocks in the USA between October 2024 and April 2025 (design: A.S. Kauer, based on APHIS data).
(Table 3), the two peaks at weeks 48/2024 and 4/2025 were mainly due to two outbreaks in large flocks of 223,000 and 300,000 birds in Minnesota (Figure 6c).
The highest ever losses of laying hens during an outbreak and the resulting problems in supplying eggs to the population to a reasonable price, led to public protests and forced government action.
Legislative and industry response
In December 2024, APHIS published an update of the indemnity program for HPAI on poultry farms that ties future compensation to certain conditions. For example, it requires that an affected premise can only be repopulated after it has passed an APHIS biosecurity audit. It also requires an audit of commercial poultry farms within a 7 km radius of an affected farm prior to movement of poultry onto a premise if the owner wishes to be eligible for future indemnity. In addition, no compensation will be paid if animals are moved onto a premise in an active restriction zone and an infection occurs within 14 days after the restriction zone is lifted. If a farm does not implement the biosecurity improvements proposed by APHIS, it will lose its right to compensation in the event of an avian influenza outbreak. The new legislation is intended to improve
biosecurity on poultry farms2. On February 18th, 2025, a group of 16 senators from both parties wrote a letter to the Secretary of Agriculture calling for the development of a forward-looking strategy regarding the development of vaccines and their use in laying hen and turkey farming, as well as the conduct of field trials with such vaccines. In addition, negotiations should be initiated with trading partners to convince them of the need to vaccinate poultry flocks and that a vaccination should not hinder or prevent the trade of poultry products3.
In April 2025, the USDA committed $100 million to enable scientists to develop new vaccines to protect poultry flocks and to study the spread of the AI virus in wild birds and in livestock. This should, if not prevent a recurrence of an epidemic, at least reduce its size4
Data source and cited literature
APHIS: Confirmations of Highly Pathogenic Avian Influenza in commercial and backyard flocks. https://www.aphis.usda.gov/livestockpoultry-disease/avian/avian-influenza/hpaidetections/commercial-backyard-flocks.
APHIS: APHIS Announces Updates to Indemnity Program for Highly Pathogenic Avian Influenza on Poultry Farms.https://www.aphis. usda.gov/news/agency-announcements/aphisannounces-updates-indemnity-program-highlypathogenic-avian.
Windhorst, H.-W.: Economic impacts of the AIoutbreaks in the USA in 2015. A final evaluation of the epizootic disaster. In: Zootecnica International 38 (2016), no. 7, p. 34-39.
Windhorst, H.-W.: A documentation and analysis of the AI epidemic in the USA in 2022. In: Zootecnica International 45 (2023), no. 3, p. 8-17.
Windhorst, H.-W.: Third Avian Influenza outbreak in the USA within 10 years: the 20232024 epidemic. In: Zootecnica International 46 (2024), no. 9, p. 28-33.
THE EFFECT OF HOT AND COLD HATCHER TEMPERATURE PROFILES
ON HATCHABILITY AND CHICK QUALITY
An eggshell temperature of 100°F (37.8°C) is widely accepted as optimal for embryonic development from the start of incubation up until transfer time. Eggshell temperature control in the setter has therefore become common practice to achieve optimal results. But what about the hatcher phase: Is an eggshell temperature of 100°F also the optimal setpoint after egg transfer? This article discusses the results of a Petersime trial that investigated three hatcher temperature profiles and their effect on hatchability and chick quality.
Temperature: the most important incubation parameter
It is commonly accepted that an eggshell temperature of 100°F (37.8°C) is optimal during the setter phase. Hence, most modern single-stage setters have adequate devices that monitor the eggshell temperature throughout the incubation process, steering the machine to meet the needs of the embryos. For instance, OvoScan™-controlled setters use infrared temperature measurement technology to automatically adapt the machine air temperature in response to the actual eggshell temperature.
At around day 18 of incubation, all viable eggs are transferred from the setter into the hatcher, which is known to be a harsher environment. Consequently, the question often arises if the reference value of 100°F is also the optimal eggshell temperature setpoint during the hatcher phase. The answer is unfortunately not so easy to give because of some practical limitations to monitor the eggshell temperature inside a hatcher:
• Eggs move around freely in hatcher baskets, which makes it more difficult to use data loggers or scanning units.
• Air humidity levels are usually higher during hatching.
• Chick meconium and fluff can be a problem as they
can cause sensor devices to become wet, dirty or even blocked.
• There are increased levels of dust, which makes it hard to get accurate measurements with infrared technology.
• Sensor devices can easily be damaged by chicks walking and pecking around. Moreover, manual eggshell temperature measurement requires the hatcher doors to be opened, which would critically disturb the hatching conditions. As a result, the usual practice is to apply pre-programmed hatcher temperature profiles based on the hatchery manager’s experience (e.g. by taking into account the specific breed, flock age, egg size, etc.).
Hatchers: more than merely a ‘finishing machine’
Even though the hatcher phase makes up only three days of the total incubation time, this period has a significant impact on the hatch outcome. It is therefore essential to define which hatcher conditions produce the best hatchability and result in chicks of the highest quality. With good incubation program management,
the hatcher will enhance and optimize what has been achieved in the setter.
Various parameters affect the hatch outcome, but the aim of Petersime’s current trial was to investigate the effect of deviations in eggshell temperature of +1.5°F and -1.5°F from the theoretical optimum of 100°F inside a hatcher. The trial was carried out by conducting a series of smallscaled incubation cycles consisting of 900 uniformly sized eggs per cycle. All eggs were obtained from Ross308 broiler breeder flocks between 30 and 40 weeks old. During the first 18 days of incubation, the eggshell temperature was controlled at 100ºF. After 18 days of incubation, the eggs were candled and all viable eggs were randomly grouped and transferred into three identical hatchers, each with a different target eggshell temperature:
1. Cold group: target eggshell temperature of 98.5°F (36.9°C)
2. Standard group: target eggshell temperature of 100°F (37.8°C)
3. Hot group: target eggshell temperature of 101.5°F (38.6°C)
Aside from the machine air temperature, the environmental parameters in all three hatchers were similar. The eggshell temperature was monitored in real time by means of wired contact sensors (with ±0.1°F accuracy) and the machine air temperature was regularly adjusted to maintain the desired eggshell temperature setpoint. At incubation day 19 and 19 hours (which was taken as a reference point for the first chicks to emerge from their shell), the target eggshell temperature of the three hatchers was again equalized and a standard hatcher temperature profile was followed until the end of incubation at 21 days. The reason for this is that once chicks start to hatch and move around, eggshell temperature measurements are no longer stable. So, the eggshell temperature deviations between the three trial groups effectively happened between day 18 and day 19 and 19 hours.
Results and discussion
1. Hatchability
The mean Hatch-of-Fertile results - summarized in Table 1 - show no significant differences in percentage due to
■ Table 1 – Mean hatch-of-fertile results
the eggshell temperature deviations between the moment of transfer (day 18) and the beginning of hatch (day 19 and 19 hours). However, a closer inspection (cf 2. Chick quality) will confirm that 100°F is to be considered as the optimal eggshell temperature from set to hatch.
Contrary to the expectation that even a slight eggshell temperature deviation would significantly affect the hatch percentage, the results of the trial show otherwise. The 18-day-old/19-day-old embryos coped well with the ±1.5°F deviations and succeeded to hatch. This might be explained by the evolution in embryo thermoregulatory capacity. During the first two weeks of incubation, an embryo is poikilothermic, which means it has an absolute low tolerance to any temperature deviations. As of incubation day 14, the transition to the homeothermic phase begins. At 7 to 10 days post-hatch, a new-born chick has transformed into a homeotherm organism that can regulate its body temperature within certain limits.
2. Chick quality
As it is logical to assume that an embryo facing deviating eggshell temperatures has to ‘compensate’, causing other possible issues, we have also investigated how the same eggshell temperature deviations influenced navel quality, the prime indicator for chick quality. A good-quality navel is closed, dry and free of eggshell and membrane residues. A poor-quality navel is a potential place for bacteria to enter the most sensitive part of the body cavity, which drastically increases susceptibility to diseases and the risk of post-hatch mortality.
(SD = 0.9)
* SD = the standard deviation indicates the dispersion of the sample data from the mean
Below is described how the ‘navel quality score’ for the trial was divided into three categories:
➔ A-quality: The navel area has healed well. Running a finger over it, you will hardly feel it. It is dry, smooth and almost flat.
➔ B-quality: The navel has not healed properly and is wet or leaking. It feels rough to the touch and has a dark button or small string.
➔ C-quality: A badly healed navel has a protruding, large dark button or a long string of non-absorbed membrane.
would be included as saleable chicks together with the A-quality chicks.
Figure 1 illustrates the average hatch percentages per trial group (Cold; Standard; Hot), but split by A-B-C chick quality categorization. These results show that relevant differences have been recorded.
The mean A-quality hatch percentages are higher for the Standard group (55.1%), followed by the Cold group (53.7%). At the same time, there is a significant drop in the results for the Hot group (43.7%). Moreover, the Hot group
■ Figure 1 – Average hatch percentages per trial group (Cold; Standard; Hot), split by A-B-C chick quality categorization.
Important to note is that the A-B-C classification for navel quality used in the trial is not the same as the chick quality standards used during daily quality control in commercial hatcheries. In the trial, the navel details were individually checked and scored. The C-quality chicks from the trial would be discarded as culls during chick grading at the hatchery, whereas the B-quality chicks from the trial
shows a higher mean percentage of C-quality chicks (9.2%).
To summarize, the trial results suggest two important findings:
• The effect of eggshell temperature deviations in the hatcher is more substantial on chick quality than on hatchability.
• Post-transfer eggshell temperatures exceeding 100°F do greater harm to navel quality than lower eggshell temperatures. The reason for this high temperature sensitivity might be found in an accelerated hatch: Heat speeds up the hatching process, which possibly results in insufficient time for proper yolk absorption and for the navel to heal properly.
Conclusion
It is recommended to primarily target an eggshell temperature of 100°F (37.8°C) after egg transfer to achieve optimal results. A slightly lower eggshell temperature will also generate acceptable hatch results and adequate chick quality. However, high eggshell temperatures – for instance exceeding 101.5°F (38.6°C) – should be avoided.
MANAGEMENT
COMPARING HEN PERFORMANCE DURING AN EXTENDED LAYING CYCLE BASED ON HEN BODY WEIGHT
This study evaluated the performance of Hy-Line Brown hens with different body weights (BW) up to 100 weeks of age. Hens in the lowest BW quartile (Q1), which aligned with breed standards, showed the most efficient feed conversion, consistent egg production and better internal egg quality compared to heavier hens. Hens of the highest BW quartile (Q4) produced heavier eggs but with lower internal quality and a tendency for thinner shells. These findings support maintaining hen BW at breed-standard levels to optimize egg quality and production efficiency in extended laying cycles.
➤ W.I. Muir1, Y. Akter1, K. Bruerton2 and P.J. Groves3
1 School of Life and Environmental Science, Faculty of Science, Poultry Research Foundation, The University of Sydney, Camden, NSW 2570, Australia; wendy.muir@sydney.edu.au
2 PO Box 1362, Elanora, Queensland, 4221, Australia
3 Sydney School of Veterinary Science, Faculty of Science, Poultry Research Foundation, The University of Sydney, Camden, NSW 2570, Australia
Summary
Commercial egg-laying hens that have incremental increases in body weight (BW) throughout the laying
phase are prone to irregular persistency of lay and the production of large eggs with poor shell quality. They continue to accumulate abdominal fat through the laying cycle which typically ceases when they are 72-78 weeks of age (WOA). The table egg industry is moving towards extending the laying cycle until 100 WOA. In this study, the performance of Hy-line Brown hens, grouped based on BW, was assessed through to 100 WOA. The hens were housed in individual cages in a high-rise layer shed under 16 h light, with ad libitum access to feed and water from 17.5-100 WOA. They were retrospectively allocated to four BW quartiles at 62 WOA, i.e. quartile 1 (Q1), the lightest hens, BW 1.99 kg to quartile 4 (Q4), the heaviest hens, BW 2.53 kg. Hen BW and egg weight (EW) had
been measured at 72 and 100 WOA and cumulative feed intake (FI), egg production (EP), cumulative egg mass (EM) and cumulative feed conversion ratio (FCR) were calculated for each BW Quartile from 17.5 WOA until 61, 72 and 100 WOA. Egg characteristics of Haugh unit (HU), relative dry shell weight, shell thickness and shell breaking strength were measured at 76-80 and 96-100 WOA. At 62, 72 and 100 WOA the BW of hens in each quartile were different with Q1 BW matching the breed standard BW for age. At 100 WOA, average BW was 2.04, 2.24, 2.40 and 2.64 kg for Q1, Q2, Q3 and Q4 respectively. Concurrently EW was 63.5, 63.9, 63.9 and 66.8 g; cumulative FI was 64.1, 65.1, 67.8 and 70.2 kg; cumulative EP was 509, 513, 518 and 482 eggs, cumulative EM was 28.9, 29.4, 30.1 and 28.3 kg, and cumulative FCR was 2.23, 2.23, 2.27 and 2.70 kg/kg respectively. At both 76-80 and 96-100 WOA eggs from Q4 birds were the heaviest but with the lowest HU. At 96-100 WOA the shell of eggs from Q4 hens was numerically (P=0.067) thinner than the eggshell of Q1-Q3 hens. There were no differences in relative dry shell weight nor eggshell breaking strength. These outcomes support management of egg-laying hens to maintain their BW at breed standard recommendation for age. i.e. Quartile 1. Compared to heavier hens, Q1 BW will achieve efficient production of good quality eggs.
Introduction
Hen body weight (BW) impacts feed intake (FI), feed efficiency and egg characteristics (Harms et al., 1981). Egg weight and egg production (EP) are central to commercial egg-laying hen performance and FI is pivotal to these outputs. However, higher FI is not necessarily associated with higher EW (Anene et al., 2021) or egg production (Cerolini et al., 1994; Lacin et al., 2008). However, higher hen BW is generally associated with higher FI, poorer feed efficiency (Lacin et al., 2008; Akter et al., 2018) and an increase in the number of abnormal eggs (Anene et al., 2021).
Studies of individually housed hens held under similar management and dietary conditions have shown considerable variation in their BW, FI, and feed efficiency (Akter et al., 2018; Muir, 2023). These variations can be evident early in the laying period, persisting through to mid-lay i.e. 40 WOA (Anene et al., 2021) and late lay i.e. 69 WOA (Muir et al., 2022).
Given the interest of the egg industry in extending egg production cycles to when hens are 100 WOA (Bain et al., 2016) and the inclination for heavier hens in the Australian industry (Muir et al., 2023a), evaluation of BW effect on FI, EP, FCR and egg quality through an extended egg production period is required. Data on hen performance and egg quality through an extended laying cycle of hens became available from a study that
involved several lighting and feeding treatments during rearing (Muir et al., 2023b; Muir et al., 2024). Analysis of BW data when the hens were 62 WOA identified hens of a range of BW with each rearing treatment group. This presented an opportunity to explore the impact of differences in BW on performance and egg quality to the end of an extended laying cycle. The main study followed the original experimental design until hens were 100 WOA (Muir et al., 2024). Then, irrespective of their rearing treatments, the flock was retrospectively divided into four BW groups or quartiles (Q), based on BW at 62 WOA. The data were then analysed to assess the effect of hen BW in late lay on cumulative FI, EP, egg mass (EM), FCR and egg characteristics throughout an extended laying cycle.
Materials and methods
Hy-line Brown hens were housed in individual cages (25x50x50 cm) in a high-rise layer shed under 16 h light/24 h. From 17.5 until 100 WOA they had ad libitum access to layer diets appropriate for their stage of EP. Each hen’s individual EP, FI and the weight of each egg was measured. Subsequently EM and FCR were calculated. At 62 WOA, all 426 hens had been weighed. BW was used to retrospectively allocate hens to four BW quartiles (Q). The BW range, average BW and number of hens in each quartile are presented in Table 1. At 62, 72 and 100 WOA hen BW and EW were determined and cumulative FI, EM and FCR from 17.5 to either 61, 72 or 100 WOA were determined for each BW quartile (Table 2). At 76-80 and 96-100 WOA, 12 eggs from each of the BW quartiles were assessed for Haugh unit (HU), shell thickness, relative dry shell weight and shell breaking strength, as described by Muir et al. (2023a). All data were analyzed using a Oneway ANOVA on generalised linear model procedure of STATISTICA Version 6 (Statsoft Inc. 2003). Means were separated by Tukey’s honestly significant difference test. Statistical significance was set at P<0.05.
Results and discussion
The allocation of hens to BW quartiles based on their BW when 62 WOA generated four distinctive groups, ranging from the lightest Q1, average BW 1.99 kg to Q4, average BW 2.53 kg (Table 1). Each quartile contained a
■ Table 1 - Hen allocation to body weight quartiles at 62 weeks of age
■ Table 2 - Hen body weight, feed intake, egg production and feed conversion for BW quartiles at 61 WOA
Observation
Cumulative feed intake (kg) (from 17.5 weeks of age)
Cumulative eggs produced (from 17.5 weeks of age)
Cumulative egg mass (kg) (from 17.5 weeks of age)
FCR (from 17.5 weeks of age)
(g/d)
Haugh unit
thickness (mm)
Eggshell breaking strength (g)
* BW measured at 62 WOA but production data were taken from 61 WOA.
a,b,c,d Rows without a common superscript are significantly different at P<0.05
similar number of hens. The BW of the quartiles were also different from each other at 72 and 100 WOA (P<0.001; Table 2). The BW of Q1 hens corresponded with the Hyline Brown recommended weight for age i.e. 2.01 kg at 72 WOA compared to recommended 1.91-2.03 kg and, 2.04 kg at 100 WOA compared to recommended 1.92-2.04 kg (Hy-line Brown Management Guide, 2018). At both ages the BW for Q2, Q3 and Q4 continued to be above breed standard weight for age.
During each period, i.e. from 17.5 to either 61, 72 or 100 WOA, Quartile 1 hens were the lightest BW group and consumed less feed in total (P<0.001) compared to Q3 and Q4. The higher FI of heavier hens has also been reported by others including Lacin et al. (2008) and Muir et al. (2023a). Further, the correlation between cumulative FI and BW when hens were 100 WOA was significant (r=0.52; P<0.005). Egg production through to 100 WOA was similar for Q1, Q2 and Q3 hens but Q4 hens produced fewer eggs than the former quartiles (P<0.001). Feed not used for hen maintenance and egg production is stored as abdominal fat, leading to ongoing weight gain, whereby the larger hens become obese, with more irregular egg quality and compromised hen health (Anene et al., 2021).
Cumulative EM was highest in Q4 hens at 61 WOA, and in Q3 hens at 100 WOA, with no differences when hens were 72 WOA. At 100 WOA the higher cumulative EM of Q3 hens was different to Q4 cumulative EM only. Cumulative EM produced by Q1 and Q2 hens to 100 WOA was not different to Q3 or Q4 hens, nor to each other. From 17.5 – 100 WOA the cumulative FCR of the Q1, Q2 and Q3 hens were similar, all being lower than the cumulative FCR of Q4 hens (P<0.001). This corresponds with other recent studies where lighter ISA Brown hens had lower FCR than their heavier counterparts at 55 WOA (Akter et al., 2018) and 69 WOA (Muir et al., 2022).
The heavier hens (Q4) produced the heaviest eggs, reflecting the observations of Muir et al. (2022) but contrary to Akter et al. (2018). Further, the heavier eggs of Q4 hens had the lowest HU (P=0.014; Table 2). Aligning with Muir et al. (2022), eggshell breaking strength and relative
shell weight did not differ due to hen BW. However, at 96-100 WOA, the eggshells of the heavier Q4 hens were thinner (approaching significance, P=0.067) compared to the eggshells of the hens in Q1, Q2, and Q3.
Conclusions
Overall, compared to lighter hens, heavier hens consume more feed but without a corresponding increase in egg production. While their eggs are heavier, their FCR is notably poorer. Hence it is recommended that hens are maintained close to the breed standard weight for age throughout an extended laying cycle. This will optimise FI and FCR while maintaining good egg size and eggshell quality without compromising egg production.
Acknowledgment: Thank you to Australian Eggs for funding this research.
References
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Bain MM, Nys Y & Dunn IC (2016) British Poultry Science 57: 330-338.
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Muir WI, Akter Y, Bruerton K & Groves PJ (2023a) Poultry Science 102:102338
Muir WI, Akter Y, Bruerton K & Groves PJ (2023b) Proc. Aust. Poult. Sci. Symp. 34: 201-204.
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Statsoft Inc. (2003). STATISTICA (data analysis software system) version 6.
From the Proceedings of the Australian Poultry Science Symposium 2025, by courtesy of the Poultry Research Foundation.
INCORPORATING AN ESSENTIAL OIL AND SAPONIN BLEND AS PART OF AN EFFECTIVE COCCIDIOSIS
MANAGEMENT
PROGRAM
Coccidiosis continues to be a top challenge in the poultry industry and growing evidence of reduced sensitivity to traditional anticoccidials like ionophores and chemicals drive the need for solutions. Here we evaluate different programs for managing coccidiosis utilizing traditional anticoccidials and an essential oil and saponin blend under different challenge conditions in broilers.
➤ S.M. Ramirez, C. Bortoluzzi2, V. Ocelova3, B. Lumpkins4, and G.R. Murugesan5 1dsm-firmenich, Switzerland, shelby.ramirez@dsm-firmenich.com
4Southern Poultry Feed and Research, United States, southernpoultry@gmail.com 5dsm-firmenich, Switzerland, raj.murugesan@dsm-firmenich.com
Introduction
The estimated cost associated with coccidiosis is between 10 and 16 billion USD globally (Blake et al., 2020). The economic cost associated with coccidiosis is not only derived from the cost of therapeutics and prophylactics such as ionophore and chemical coccidiostats, but also the associated and performance loss. Eimeria spp., can also be predisposing factors to secondary bacterial challenges that could also increase the economic impact. For several decades, chemicals, ionophores and chemical/ionophore blends have been available and used to control coccidiosis. Given the lack of new coccidiostat development and the increase in anticoccidial resistance observed in Eimeria, producers have been seeking alternative solutions to managing coccidiosis. Eimeria spp. directly damage intestinal integrity which is associated with poorer nutrient digestion and absorption and inflammation (Souza et al., 2024). Therefore, managing coccidiosis can consider both the direct and in-direct challenges of Eimeria spp. infections.
Both saponins (Alghirani et al., 2022) and essential oils derived from oregano (Guar et al., 2018) have anti-parasitic properties whereas citrus oil has been demonstrated to be anti-inflammatory (Yang et al., 2023). Specific essential oils and saponins were selected and formulated into an essential oil + saponin blend (EOS) based on their functional properties that support birds through a coccidiosis challenge. This EOS blend was evaluated under various Eimeria or Eimeria + Clostridium perfringens challenge models and compared to traditional coccidiosis management strategies.
Method
Two studies were conducted to evaluate a commercially available product (AccuGutTM C.1, dsm-firmenich, Animal Nutrition and Health, Switzerland) compared with traditional coccidiosis management programs. This commercially available product contains a proprietary blend of phytogenic compounds from oregano, citrus, and Yucca schidigera.
Study 1 utilized Cobb 500 males in a 42-day trial with 4 treatments and 7 pens per treatment containing 25 birds per pen raised on used litter. The dietary treatment groups are outlined in Table 1 and dietary treatments were supplemented on top of a corn-soybean meal based basal diet. All challenged groups were given 5,000 oocysts Eimeria maxima orally per bird on day 14 and 1.0 × 108 CFU of Clostridium perfringens per bird applied in the bottom of tube feeders on day 19, 20 and 21.
Study 2 utilized Ross 308 males in a 35-day trial with 6 treatments and 10 pens per treatment containing 25 birds per pen raised on fresh litter. The dietary treatment
■ Table 1 - Study 1 treatment groups by feeding phase
Treatment Day 0 – 21 Day 21 – 35 Day 35 – 42
Challenged control (CC) Basal diet Basal diet Basal diet
CC + Nicarbazin to Narasin (N-N)
CC + Nicarbazin to EOS (N-EOS)
Nicarbazin Narasin Narasin
Nicarbazin EOS EOS
CC + EOS (EOS) EOS EOS EOS
Nicarbazin (125 ppm)
Narasin (60 ppm)
EOS = essential oil + saponin (125 ppm)
groups are outlined in Table 2. All challenged groups were given 21,800 oocysts Eimeria acervulina, 13,300 oocysts Eimeria maxima, 5,200 oocysts Eimeria tenella orally per bird on day 14.
For both studies, performance metrics, mortality, and lesion scores on day 21 were recorded. Data were analyzed utilizing the Glimmix procedure of SAS (Study 1) and JMP (Study 2) with significance reported for P<0.05.
■ Table 2 - Study 2 treatment groups by feeding phase
numerically less in N-N, N-EOS, and EOS treatments.
In Study 2 for the 35-day period, the CC had numerically increased mortality (4.09%) compared to the NCC (1.36%) whereas each of the other treatments were intermediate and not statistically different from each other: S (2.27%), NN-S (0.45%), NNEOS (0.45%) and EOS (0.91%). Body weight gain was reduced (P<0.05) by 23 g and FCR was increased (P<0.05) by 13 points for the CC compared to the NCC. Birds that received a dietary treatment (S, NN-S, NN-EOS, or EOS) were numerically intermediate the NCC and CC and were not statistically different from each other.
Discussion
Treatment Day 0 – 21 Day 21 – 35
Non-challenged control (NCC) Basal diet Basal diet
Challenged Control (CC) Basal diet Basal diet
CC + Salinomycin (S) Salinomycin Salinomycin
CC + Nicarbazin/Narasin to Salinomycin (NN-S)
CC + Nicarbazin/Narasin to EOS (NN-EOS)
Nicarbazin/Narasin Salinomycin
Nicarbazin/Narasin EOS
CC + EOS (EOS) EOS EOS
Salinomycin (60 ppm)
Nicarbazin/Narasin (40 ppm Narasin + 40 ppm
Nicarbazin)
EOS = essential oil + saponin (125 ppm)
Results
In Study 1 for the 42-day period, N-N, N-EOS, and EOS reduced (P<0.05) the 42-day FCR compared to the CC whereas body weight gain was increased (P<0.05) for N-N and N-EOS compared to CC and EOS. Lesions scores were reduced (P<0.05) in birds fed N-N (0.14), N-EOS (0.29), and EOS (0.43) compared to the CC (0.90) and there was no statistical difference in mortality although
The challenge model in Study 1 was effective in producing lesions associated with necrotic enteritis which is one potential secondary challenge associated with coccidiosis. The lesion scores observed in the CC were relatively mild as was the mortality that were confirmed with lesions (2.85% for the CC). These would indicate the model used in this study was relatively mild; however, the performance impact was greater than anticipated. Based on the Cobb 500 guidelines, males should have a body weight gain of 3.5 kg and cumulative feed conversion of 1.53 by 42-days. In Study 1, CC birds body weight gain was 2.2 kg with a cumulative feed conversion of 1.94 which is a 37% and 27% reduction, respectively, compared with the breed standard. Although we cannot deduce if the performance reduction was solely based on challenge, it is a relatively large deviation from the performance guideline. Incorporating Nicarbazin in the starter feed with either EOS or S inclusion in the grower and finisher phases was effective in increasing body weight gain and reducing feed efficiency for the 42-day period indicating that both programs could be effective solutions. Nicarbazin has continued to be an effective solution against coccidiosis; however, the mode of action is poorly understood (Noack et al., 2019). There is also some evidence to suggest that there may be development of reduced sensitivity to nicarbazin in some regions (Kraieski et al., 2021).
In Study 2, two commonly used programs (Salinomycin in the starter and grower) and a Nicarbazin/Narasin blend in the starter and shuttled to Salinomycin in the grower) were evaluated and compared with a Nicarbazin/Narasin blend in the starter shuttle to EOS in the grower and EOS in the starter and grower. The challenge model used in this study was slightly more severe compared with Study 1 in terms of mortality, but less in terms of performance with only a 12% reduction in body weight gain and 7% reduction in FCR. Given that all of the mitigation strategies had a response that was intermediate in value compared to the NCC and CC, we can conclude that these programs were effective in increasing performance in this study.
Kraieski et al. (2021) also concluded that FCR appears to be a good indicator for sensitivity for anticoccidials. This is in agreement with Souza et al. (2024) that demonstrated the relationship between Eimeria challenge on intestinal integrity and the associated impact on nutrient digestion and absorption, inflammation, and susceptibility to other diseases that would ultimately reduce the efficiency of which nutrients and energy are utilized for growth.
Conclusion
By incorporating the essential oil and saponin blend in a shuttle or standalone program, birds showed improved body weight gain and feed efficiency compared to the challenged control groups in this study. The increased prevalence of anticoccidial resistance in Eimeria further drives the need to incorporate rotation (from one production cycle to the next) and shuttle (within one production cycle) programs and other solutions like
essential oil and saponin blends that can be considered as part of effective coccidiosis management programs.
References
Alghirani MM, Teik Chung EL, Abdullah Jesse FF, Sazili AQ & Loh TC. (2022) Journal of Poultry Science. 10(2): 215-226.
Souza GC, Esteves GF, Volpato FA, Miotto R, Mores MAZ, Ibelli AMG, & Bastos AP (2024) Poultry 3: 1–14.
Yang J, Lee SY, Jang SK, Kim KJ, & Park MJ (2023) Pharmaceutics 15: 1595.
From the Proceedings of the Australian Poultry Science Symposium 2025, by courtesy of the Poultry Research Foundation.
2024 AVIAN METAPNEUMOVIRUS OUTBREAK IN THE UNITED STATES
Avian metapneumovirus is a highly contagious RNA virus that typically affects turkeys, chickens and ducks but can also impact pheasants, pigeons, guinea fowl and various wild birds.
➤ Tom Tabler, Professor and Extension Poultry Specialist, Department of Animal Science, University of Tennessee
The virus is mainly associated with upper respiratory tract infections (turkey rhinotracheitis in turkeys and swollen head syndrome in chickens) leading to clumping and loss of cilia, which predispose the birds to secondary bacterial pathogens resulting in severe respiratory signs, high morbidity and mortality. The reproductive system also may be infected, resulting in a significant decrease in egg production (up to 70 % in breeder turkeys) and egg quality (poor shell quality, pale color, chalkiness and misshapen eggs) (VanBeusekom, 2024). Four subtypes of the virus (subtypes A, B, C, and D) are recognized, with subtypes A and B widespread in turkey and chicken producing countries around the world. The 2024 outbreak has consisted of two distinct subtypes. States in the eastern U.S. have been affected by aMPV subtype B, while western states have been affected by aMPV subtype A. All detections in previous years from aMPV were from subtype C.
Background
Avian metapneumovirus was first detected in turkeys in South Africa in 1978. A few years later it was reported in the United Kingdom and then quickly spread throughout much of Europe, including Spain, France, Germany, Italy and Hungary. The virus was undetected in the U.S. until 1996, when the subtype C was diagnosed in commercial turkeys in Colorado and later in Minnesota. Until 2024, previous sporadic outbreaks of aMPV subtype C occurred in turkeys across the upper Midwest.
However, the situation changed in January 2024, when reports of severe respiratory disease outbreaks started coming in from chicken and turkey flocks in North Carolina and Virginia. The cause was identified as aMPV subtype B, the first detection of this subtype in the U.S. Later surveillance revealed detection in Texas, California and
numerous other states of aMPV subtype A, also a first for this subtype in the U.S. These new subtypes then spread rapidly across North America and, in less than six months, subtypes A, B or both A and B were confirmed in 26 states and two Canadian provinces (Manitoba (May 2024) and Ontario (June 2024) (Figure 1). Subtypes A and B cause disease in both chickens and turkeys, whereas subtype C seems to infect mainly turkeys and, to a lesser extent, ducks. Subtype A can spread through a flock extremely rapidly, with an entire flock potentially becoming sick within just one day, while the other subtypes can spread more slowly, depending on a variety of factors (VanBeusekom, 2024).
Methods of disease spread
Avian metapneumovirus spreads horizontally. Direct contact between animals is the most important method of aMPV transmission within flocks. Indirect spread on contaminated fomites and the movement of birds, people, feed trucks and equipment from infected to susceptible farms has been implicated in the spread of the virus. Airborne transmission also is possible, and birds are usually infected through inhalation of virus infected aerosols, especially respiratory secretions (Cook et al., 1991; Alkhalaf et al., 2002; Jones and Rautenschlein, 2013). Migratory wild birds and pigeons are considered natural reservoirs of infection and may play an important role in the spread of the disease. Wild migratory birds have been implicated in the spread of aMPV in many countries (U.S., Canada and many European countries), which may explain the coincidence of main outbreaks of the infection occurring with migratory periods (Shin et al., 2002). Currently, there is no conclusive evidence of vertical transmission from the hen to her progeny through the egg.
AMPV attacks the respiratory system
Birds appear to shed aMPV for only a few days after infection, making it quite difficult to find when trying to detect it. Avian metapneumovirus attacks the birds
through the respiratory route and damages the cilia that line the respiratory tract and causes immune suppression. This opens the door for other pathogens and makes the bird more susceptible to secondary bacterial infections, resulting in more severe respiratory disease and increased mortality. Good management is critical to limit the damage should a flock become infected with aMPV. Growers must maintain optimal humidity and air quality parameters and keep the poultry houses well-ventilated. Management factors play a key role in severity, and the disease is made worse by poor environmental conditions, with significantly more severe disease and higher mortality seen on farms that are poorly managed and those with poor ventilation. Turkeys are more severely affected than chickens, and younger birds are more susceptible to the disease than older birds. The entire flock (100%) may have the disease, but mortality rates can vary greatly, ranging from 0.4% to 50% or more, especially in young turkey flocks with secondary bacterial infections.
What to look for
In turkeys, the disease is usually seen in birds between 3 to 12 weeks of age, but birds of all ages are at risk of infection. Symptoms include swelling of the face, coughing, conjunctivitis, wet eyes, head shaking and neurological signs (twisted necks and “star gazers”). Neurological signs result from bacterial infections of the middle ear, skull and brain (Manginsay, 2024). As mentioned
▲ Figure 1 - Map of avian metapneumovirus subtype A, B and C detections in the U.S. (Source: Steven Clark, aMPV Working Group)
previously, infected birds often suffer from secondary bacterial infections caused by pathogens such as E. coli, Ornithobacterium rhinotracheale (ORT) and cholera. A preliminary diagnosis in the field might be considered by clinical signs and lesions observed at necropsy. However, several diseases can be confused with aMPV infection in turkeys (Kaboudi and Lachheb, 2021). Laboratory investigations are essential to confirm the disease (Figure 2) because of the emergence of co-infection, involvement of multiple environmental factors and the risk of secondary bacterial infections.
Samples should be taken as soon as possible after the beginning of symptoms. Again, isolation of aMPV is generally very hard after the first week of disease because of the secondary bacterial infections. In addition, the
▲ Figure 2 - Diagnosis approach to aMPV infection in turkeys (Source: Kabousi and Lachheb, 2021)
Good
management is critical to limit the damage should a flock become infected with aMPV. Growers must maintain optimal humidity and air quality parameters and keep the poultry houses well-ventilated
excretion of virus from damaged tissues occurs for only a short time after infection (Cook et al., 2001).
In the current outbreak, most cases in chickens have involved 4- to 9-week-old broilers and broiler breeders. Older broiler breeder flocks (older than 40 weeks) have reported more severe disease with higher mortality (Manginsay, 2024).
Respiratory signs typically appear three to five days after infection. Egg production drops and elevated mortality are common in broiler breeder and layer flocks. Neurological signs often appear in some birds from affected flocks that include loss of coordination, head shaking, twisted necks and star gazing. Within a few days of the first respiratory symptoms, birds will develop swollen sinuses, swelling around the eyes and/or swelling of the entire face/head. Hens are often more affected than roosters in broiler breeder flocks, and widespread secondary bacterial infections may be evident in mortality. In broilers, decreased feed and water consumption are typically noted. Evidence of secondary bacterial infection is often present at necropsy, mainly resulting from E. coli. Increased processing plant condemnations often occur in broiler chickens. Egg production losses are worse in turkeys (losses of 10% to 40% are not uncommon in turkeys) than in broiler breeder and table egg flocks (0.5% to 10%). Egg quality changes that may include a loss of pigmentation and eggshell deformities are possible and have been reported internationally but appear rare in the current U.S. outbreak.
Summary
Like many other diseases, the best defense to ensure that aMPV is not introduced onto the farm is a rigorous biosecurity program and management practices. Avian metapneumovirus has spread rapidly across the U.S. since January with serious impacts on poultry health. Understand that early detection of the disease is critical and remain vigilant for suspicious respiratory signs in your flock. Seek assistance at the first sign of disease.
There are no commercially available aMPV vaccines in the U.S. and no treatment for aMPV infection. Therefore, biosecurity is the best defense we have in protecting our
flocks, and its importance cannot be overstated. Isolate (as quickly as possible) any birds showing disease signs from the rest of the flock. Isolate for 30 days any birds that leave the farm and return, even if they appear healthy. Flock owners should care for heathy birds first, always wearing clean clothing and sanitized footwear. Care for isolated or sick birds last. Do not share equipment, feed and water containers, feed scoops, etc. between isolated and healthy birds. Any cages or equipment that leaves the farm should be cleaned first and then disinfected before leaving and before returning to the farm. There is no substitute for good biosecurity, and it is our first and best line of defense in disease prevention.
References
Alkahalaf, A.N., D.A. Halvorson, and Y.M. Saif. 2002. Comparison of enzyme-linked immunosorbent assays and virus neutralization test for detection of antibodies to avian pneumovirus. Avian Diseases 46:700703.
Cook, J.K., M.B. Ellis, and M.B. Huggins. 1991. The pathogenesis of turkey rhinotracheitis virus in turkey poults inoculated with the virus alone or together with two strains of bacteria. Avian Pathology 20:155-166.
Cook, J.K.A., M.B. Huggins, S.J. Orbell, K. Mawditt, and D. Cavanagh. 2001. Infectious bronchitis virus vaccine interferes with the replication of avian pneumovirus vaccine in domestic fowl. Avian Pathology 30:233-242.
Jones, R.C., and S. Rautenschlein. 2013. Avian metapneumovirus. D. E. Swayne, J. R. Glisson, L.R. McDougald, L.K. Nolan, D.L. Suarez, and V. Nair (Eds.), Pages 125-138 in Diseases of Poultry, Wiley-Blackwell, Ames, IA.
Kaboudi, K., and J. Lachheb. 2021. Avian metapneumovirus infection in turkeys: a review on turkey rhinotracheitis. Journal of Applied Poultry Research 30(4):100211
Manginsay, N.A. 2024. Avian metapneumovirus: A new threat surrounding Mississippi on all fronts. Emerging Trends 2:24-26. Mississippi Poultry Association Newsletter.
Shin, H.J., K.T. Cameron, J. A. Jacobs, et al. 2002. Molecular epidemiology of subgroup C avian pneumoviruses isolated in the United States and comparison with subgroup A and B viruses. Journal of Clinical Microbiology 40:1687-1693.
VanBeusekom, E. 2024. Combating avian metapneumovirus (aMPV). Hybrid turkey news. Available at: https:// www.hybridturkeys.com/en/news/combating-avianmetapneumovirus-ampv/. Accessed: August 8, 2024.
By courtesy of the University of Tennessee Institute of Agriculture and UT Extension
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