The Ongoing Need for this Work, as indicated by stakeholders

Poultry consumption has increased worldwide at a steady rate since 1960. Estimates for American per capita consumption of poultry are 113 pounds for 2022 with an expected increase to 114.5 pounds in 2023 (National Chicken Council, 2022). In addition, per capita poultry (chickens, turkeys) consumption in the US equals the combined per capita consumption of beef and pork. United Nations (UN) forecasters project the 2050 world population to be 9.7 billion people, increased from the 2022 population of 8.0 billion people [United Nations, 2022]. Producing protein to feed this number of people will require economical systems that have environmental sustainability. Poultry fit both criteria because of high feed efficiency. In order to meet this ever-increasing food demand for the growing human population, poultry breeders, scientists and producers seek to provide consumers with a safe, wholesome product with higher production efficiency, lower production cost combined with high welfare standards.

Disease remains a significant issue for the poultry industry. Morbidity, poor performance, and mortality cause significant economic losses combined with the human health threat attributable to bacterial and viral zoonotic pathogens. The impact of diseases is one major impediment for sustained productivity despite advances in poultry pathogen control. Economic impacts of disease in the poultry sector can be divided into production and prevention. Poultry production impact includes losses due to mortality, decreased meat and egg production, and condemnations at processing, Prevention impact encompasses the increased costs in vaccinations, biosecurity, and eradication programs for exotic diseases. Maintaining sustainable production by understanding and optimizing immune function has reached critical importance due to increased focus on antibiotic free (ABF) or organic production as well as the re-emergence of previously controlled pathogens.

The project goal of improving poultry health will reduce the need for antibiotics and other drugs which aligns with the producers’ goal of judicious antibiotic use to produce poultry meat and eggs. Animal production, the environment, and poultry wellbeing are challenged by the use of pharmacological agents (e.g., antibiotics) to treat disease. For organic production, the project aligns with the goal of healthier animals, reducing disease incidence and ameliorating welfare issues.

Meat and egg producers place high priority on protecting poultry flocks against endemic and exotic diseases. Two U.S. outbreaks of highly pathogenic avian influenza (HPAI) in 2015 and the current one in 2021-2022 reminds us of system vulnerabilities. Avian influenza has been detected in commercial and backyard chickens across 39/50 states during the current outbreak. A major outbreak is expected for the 2022-2023 season due to the amount of virus in wild birds. In addition, the risk for exotic disease introduction is also elevated by consumer preferences driving commercial production systems to be more open (free range and cage free). The U.S. Poultry and Egg Association (USPEA) defines multiple research priorities for controlling disease and ensuring food safety in poultry. These priorities seek to reduce antibiotic, pesticide and anti-parasitic drug use through a focus on disease prevention, genetics, welfare, nutrition and hatchery management.

This project addresses the genetic bases of disease resistance and immunity in poultry. The work also seeks mechanistic understanding of innate and adaptive immune processes; issues having fundamental importance. Poultry breeding, vaccine, and allied animal health industries are the most immediate users of these data, reagents, and tools generated from project research. These primary stakeholders are frequent participants through attendance at annual technical committee meetings as well as their many collaborative research efforts with the members. Interaction as described signifies the high value that stakeholders ascribe to this project.

The importance of the work

A sustainable poultry industry which can increase production to feed a growing world population needs disease prevention and control strategies. Natural selection produces genetic variability in populations. This multistate project fills this crucial need by enhancing stakeholders’ knowledge of the genetics of resistance and immunity to poultry diseases. Stakeholders can improve their stocks by applying this knowledge of genetic variability and disease resistance to augment desired traits while eliminating unwanted characters. Genetic responses to disease may be controlled by one or a few genes. The major histocompatibility complex (MHC) is the primary example. Responses may be more complex because many genes contribute to the overall response. Low heritability, a consequence of multigene control makes improvement through traditional selection.

Knowledge gaps about polymorphic loci and their interactions persist, despite completion of multiple chicken genome sequences. This project effort will facilitate understanding of immune responses to common poultry pathogens. The knowledge gained will enhance development of targeted responses providing protection.

Both large-scale and small-scale poultry production face multiple limiting factors. Disease impacts in both systems have been exacerbated by efforts to reduce antibiotic use plus managing birds in less-controlled environments. Production has been disrupted by recurrence of diseases that once seemed to be controlled along with emerging pathogens. Without this project’s work to study the important issues of environmental and physiologic factors that impact immune system development, optimal immune function and disease resistance, disease will increase, production efficiency will decrease, food safety will be greatly compromised, and export markets will be closed to products.

Unlike model species in biomedical research, few poultry research reagents are available through commercial sources. In addition, genetic resources, such as stocks that enable experiments to answer critical questions, are limited. The multistate objective focuses on resource development (methods, reagents, specialized genetic stocks) that will facilitate immune system assessment. Morbidity and mortality could increase if immune development is not monitored to prevent deterioration of immune responses to vaccines and disease organisms. Poultry breeding companies will have direct application for methods to address genetic and environmental factors that impact the immune system. Production companies will realize lower production costs benefit through improved health and effective responses to vaccination.

The Technical Feasibility of This Project

Technical committee members for NE-1834 cross multiple disciplines including genetics, genomics, immunology, infectious diseases, microbiology, virology, poultry medicine, physiology, kinomics, nutrition, biochemistry, and molecular biology. The committee’s expertise enables individual and collaborative research which is essential for the future of poultry production. Methods that have demonstrated success in other species, i.e. humans, have been adapted to poultry work. Development of other sophisticated methods have enabled examination of gene expression and interaction that may affect disease resistance. Defined genetic stocks can be studied with techniques such as next generation sequencing and gene editing to understand responses against disease. Project participants are leaders in their respective specialties. The work is technically feasible, and the necessary infrastructure exists for members’ success in completing the work. A final necessary component is adequate financial support for the proposed effort.

Advantages for doing the work as a multistate effort (The Essential Collaborative Nature of this Project)

Project members conduct studies on genetic resistance to disease across multiple disciplines. Operating through the multistate system offers the advantage of shared resources that synergize to address critical scientific questions. No one station or participating laboratory has the range of expertise, facilities, equipment and biological resources to investigate the crucial scientific questions for the project. The effort is enhanced by the unique skills of the project members. Some stations have specialized genetic stocks or reagents (antibodies, cell lines, pathogen stocks), that are shared with the scientific community. Genetic stocks (inbred lines, congenic lines, selected lines) have facilitated many experiments that have answered key questions on disease resistance and the immune response. The value of these resources cannot be overstated. The regular interaction through the multistate committee enhances research opportunities for each participant. Networking has brought about multiple collaborations.

The current NE-1834 group of scientists each addressing complementary aspects of the genetics of resistance and immunity to avian diseases includes 23 independent laboratories representing 13 institutions across 12 U.S. states [AL, AR, CA (2), DE (3), GA (2), IL, IA, MA, MD (2), NC, OH (2), WU, and WV (2)]. Two USDA scientists (ADOL, FFSRU) and one international researcher in the Netherlands (NL) collaborate on the project. Conducting this work as a multistate effort allows for the greatest efficiency of resource use among these scientists.

Participating stations and scientists have authored 165 refereed publications and 203 abstracts, a very productive effort for the project period. Forty-three publications have joint-authorship illustrating the truly essential, cooperative, multidisciplinary nature among the NE-1834 project members. Technical committee members and collaborators from NE-1834 contributed to reference works such as Avian Immunology (Kaspers, et al, 2022) co-edited by a project member plus authorship in 7 of the 22 chapters and one of the two appendices.

In addition, five project members hold endowed faculty positions indicting the prestigious nature of their research. The Poultry Science Association (PSA) and the American Association of Avian Pathologists, scientific organizations tied most closely to the project, have awarded their highest honors to project scientists. Five project members are Fellows of the Poultry Science Association. Other awards presented to project members include the Bayer Snoeyenbos New Investigator Award. Embrex Fundamental Science Award, Evonik Degussa Award for Achievement in Poultry Science, Hy-Line International Poultry Science Research Award, Novus International, Inc. Teaching Award, PSA Early Achievement Award for Research, and two US Poultry Distinguished Poultry Industry career awards.

Synergies exist with other multistate projects. The NE-1834 project members cooperate with relevant multistate projects including NC1170: Advanced Technologies for the Genetic Improvement of Poultry and NC1180: Control of Endemic, Emerging and Re-emerging Poultry Respiratory Diseases in the United States. Multiple NE-1834 technical committee members also participate in either NC1170, NC1180 or both. One participant has been active in the NE-1834 and NC1170 technical committees for more than 34 years. Excellent communication and coordination are the primary benefits of their active participation in both projects. Duplication across projects is avoided thereby enhancing efficient resource use.

Outcomes and Impacts of this Project

Greater fundamental understanding of how the avian immune system functions, improved comprehension of immune responses to specific antigens, higher efficacy of pharmaceutical agents including vaccines; advanced vaccine programs for controlling existing as well as emerging diseases; increased knowledge of genetic selection consequences on poultry health and production; insight into polymorphic loci effects; and breeding strategies that enhance disease resistance and robustness in poultry are among the impacts expected for this project. Production efficiency, animal health and welfare will increase through improved disease resistance and better prevention strategies. These advances will produce immediate as well as long-term benefit. Consumers will favor improved poultry product safety and reduced antibiotic use. Valuable resources for stakeholders and project participants will be generated as scientific knowledge, both basic and translational, combined with new or modified tools and reagents.

References:

Avian Immunology, 3rd Ed. 2022.  B. Kaspers, K. Schat, T. Göbel, and L. Vervelde, eds. 692 pages. Elsevier, Amsterdam. ISBN: 9780128187081; https://doi.org/10.1016/C2018-0-00454-5

National Chicken Council. 2022. Per-capita-consumption-of-poultry-and-livestock. https://www.nationalchickencouncil.org/about-the-industry/statistics/per-capita-consumption-of-poultry-and-livestock-1965-to-estimated-2012-in-pounds/

United Nations Department of Economic and Social Affairs, Population Division (2022). World Population Prospects 2022: Summary of Results. UN DESA/POP/2022/TR/NO. 3.