THE NEED AS INDICATED BY STAKEHOLDERS. The United States (U.S.) is the world's largest poultry producer and the second-largest egg producer and exporter of poultry meat. The poultry industry is a highly integrated and constantly growing industry and is a major contributor to animal agriculture. The combined value of production from broilers, eggs, turkeys, and the value of sales from chickens in 2017 was $42.7 billion, up 10 percent from $38.7 billion in 2016 (USDA, ERS data, 2018).

Based on the figures published by the National Chicken Council (2018), Americans consume more poultry than anyone else in the world – 108.6 pounds per capita – being chicken the number one animal protein consumed in the U.S. Consumers rate chicken’s value very highly and chicken consumption per capita has increased nearly every year since the mid 1960’s, while red meat consumption has steadily declined.

U.S. egg operations produce over 105 billion eggs annually. Over 75% of egg production is for human consumption (the table- egg market). The remainder of production is for the hatching market. These eggs are hatched to provide replacement birds for the egg-laying flocks and to produce broiler chicks for grow out operations. U.S. per capita consumption of eggs and egg products is around 278.9 eggs per person. Chicken eggs are an important source of high quality protein and other micro nutrients in the diet.

The U.S. has the largest broiler chicken industry in the world, and over 16 percent of the production was exported to other countries in 2017. In 2017, approximately 8.9 billion broiler chickens weighing 55.6 billion pounds live-weight were produced. The U.S. turkey industry produces approximately one-quarter of a billion birds annually, with the live-weight of each bird averaging over 25 pounds. The U.S. is by far the world's largest turkey producer, followed by the European Union. Even though exports are a major component of U.S. turkey use, the U.S. consumes more turkey per capita than any other country.

Protection of poultry by effective control and prevention of diseases is critical in order to maintain wholesome poultry and poultry product markets. Such efforts will also make a significant contribution towards national and international food security.

IMPORTANCE OF THE WORK, AND WHAT THE CONSEQUENCES ARE IF IT IS NOT DONE. Respiratory diseases continue to be a major concern for the poultry industry. Consequently, losses induced by respiratory diseases in poultry are of major economic impact on the producer, the local and U.S. economies. Various pathogens may initiate respiratory disease in poultry including a variety of viruses, bacteria, and fungi. Many endemic respiratory infectious diseases in the U.S. continue to decrease the profitability of commercial poultry production. Losses are realized from mortality and morbidity via condemnation at processing and poor performance (increased feed conversion and medication costs, decreased growth). In addition, endemic, emerging and re-emerging respiratory diseases add to the economic loss to the poultry industry. Based on the USAHA report (2017), the following respiratory pathogens continue to be a problem in the industry: variant infectious bronchitis (IB), infectious laryngotracheitis (ILT), lentogenic Newcastle disease (ND), infectious coryza, avian influenza (AI), and infections caused by Gallibacterium anatis, avian mycoplasmas, Ornithobacterium rhinotracheale (ORT), Escherichia coli, and Pasteurella multocida. In addition, severe cases of infectious coryza across the U.S. and velogenic Newcastle disease virus during 2018-2019 are an alert call for researchers to focus on understanding upper respiratory dynamics in poultry.  Environmental factors and novel production systems may augment the incidence of these pathogens producing the clinical signs and lesions. Thus, preventative strategies including poultry management are critical to control the diseases mentioned above and other respiratory diseases. Because these diseases are multifactorial in nature, improved understanding of the underlying factors driving the ‘respiratory disease complex’ are necessary, including understanding the polymicrobial relationships occurring between pathogens and the normal microbiota during the disease process. This group has shifted focus in recent years towards these endeavors.

The export market comprises a large portion of the U.S. poultry meat and egg production. Export markets are subject to immediate restrictions when poultry respiratory diseases such as highly pathogenic AI (HPAI) or exotic Newcastle disease (END) are diagnosed and reported in commercial flocks. HPAI and END have been reported in the U.S. since our last project was initiated, which adds another level of complexity in understanding and preventing these exotic diseases. The magnitude of losses caused by these diseases are well illustrated by the 2015-2016 HPAI which was the most severe outbreaks in the history of the U.S. poultry industry decimating 9 and 6% of the layer and turkey population, respectively, and the 2002 outbreak of END in California affected commercial poultry and costed more than $160 million in eradication and control efforts. In 2018, virulent Newcastle disease virus (vNDV) has been detected in backyard flocks in Southern California. These viruses apparently entered through illegal bird movement as shown by molecular epidemiology tracing the outbreak virus to Central American viruses (Belize). Over 350 confirmed cases have been reported including at least 4 commercial poultry farms. An additional case in Utah has been reported and is believed to be linked to Southern California. More than a million backyard and commercial birds have been euthanized in this on-going outbreak. In terms of endemic diseases, the losses they cause are less profound but accumulate throughout an extended period of time. Researchers have calculated poultry endemic disease losses in the U.S. to be 2.31 billion in US dollars, an 8.2% of the gross value of poultry production in 2005.The agri-bioterrorism threat to the U.S. food supply is a reality after the terrorist attacks of September 11, 2001. HPAI and END viruses are classified as agri-bioterrorism agents considering the virulence, environmental stability, and transmissibility of these viruses among poultry flocks. Our project will develop strategies for rapid diagnosis and control of newly emerging and endemic diseases. Considering the challenges posed by endemic and exotic diseases, it is essential that the proposed studies proceed to help protect the world and our nation's food supply and the economic well-being of the poultry industry and our country.

THE TECHNICAL FEASIBILITY OF THE RESEARCH. The technical challenges posed by the goal of improved respiratory disease control are complex and significant, but feasible. Participants in the project have experience and training in a range of disciplines including: immunology, infectious diseases, genetics, genomics, virology, poultry medicine, physiology, biochemistry, microbiology, bioinformatics, and molecular biology. That expertise will be used to undertake the work and complete the objectives. In addition, the technical committee of this project work on the leading-edge of science and have demonstrated their expertise with the requisite infrastructure to successfully complete the described work, if sufficient financial support is made available.

THE ADVANTAGES FOR DOING THE WORK AS A MULTISTATE EFFORT. Control of respiratory infectious diseases lends itself to collaborative multistate research. The multistate effort is required for the synergistic and collaborative conduct of research that is based upon the combination of biological materials facilities, equipment and expertise from multiple stations. No single station possesses all of these to address the major scientific issues for the project. The use of a team approach enables us to perform cross-disciplinary, multi-industry research with translatable value. Proof of this are our ongoing collaborations and the Poultry Respiratory Diseases (PRD-CAP) project funded by USDA in which several of our members collaborate.  

The current NC1180 project has served as a venue for gathering, discussing, and providing critical information on disease status at the state and national level which helped to develop research and prevention strategies for the researchers, industry and state and federal government officials. The understanding of respiratory diseases of poultry has been advanced considerably through the current project. Of notable mention are the advances made in rapid diagnostics for all major respiratory pathogens which include; practical field-based tests to third generation sequencing use for rapid identification and rapid prediction of pathogenicity of pathogens exotic to the U.S. e.g. the use of this technique in the 2018-2019 vNDV outbreak shows effective collaboration between stations in GA, IA and CA. DNA and recombinant vector-based vaccine technologies have also moved forward at a dramatic pace and hold much promise for improved control of respiratory diseases. Studies with newly recognized diseases and re-emerging diseases in addition to endemic infections have led to better understanding of the disease, development of diagnostic tools, and surveillance and vaccine strategies to control these diseases. The combination of these and other findings have led to very productive years of the current project as indicated by the number of published papers including joint publications from participating institutions.

In addition, this project synergizes and collaborates closely with other projects. There is a strong cooperation between NC1180 and another multi-state project: NE1834, Genetic Bases for Resistance and Immunity to Avian Diseases. The participation of some of the members in both projects allows for excellent coordination between the two multi-state projects, ensuring good communication and collaboration while avoiding duplicative efforts.

Finally, the evolution of this collaborative group has enabled large funding to pursue deeper research questions. Through this group, a multi-million dollar research grant was obtained from USDA, the Poultry Respiratory Disease Coordinated Agricultural Project (http://www.prdcap.com). This project includes 38 investigators from all states in the NC1180 group. The goal of this project, now in year 5, is to develop knowledge-based integrated approaches to detect, control and prevent endemic, emerging and re-emerging poultry respiratory diseases in the US. Numerous projects have been funded through this effort, with significant progress towards better understanding of the respiratory disease complex and the continued development of tools by which to identify and predict disease (http://www.prdcap.com/research/).

WHAT THE LIKELY IMPACTS WILL BE FROM SUCCESSFULLY COMPLETING THE WORK. The overall impact of a successful outcome will be improved understanding of the ecology, pathobiology, epidemiology, diagnosis and control of respiratory diseases. These outcomes will not only benefit the poultry industry but also the food security of our country. Impact of this research will be derived from identification and characterization of disease agents, their reservoirs, factors involved in agent transmission to poultry, development and delivery of novel, fast and accurate molecular and protein-based diagnostics, determination of infection status, rapid strain identification or characterization, evaluation and development of vaccines, and the design and implementation of eradication protocols for select agents. The overall outcome of the project is to produce findings that enable the poultry industry to remain competitive and profitable reaching the ultimate goal of feeding the population of our country.