Performing Department
(N/A)
Non Technical Summary
Infectious diseases and heat stress, exacerbated by climate change, are two significant challenges facing the $34.68B US egg industry. Highly Pathogenic Avian Influenza (HPAI) outbreaks in the U.S. in 2014-2015 and 2022 resulted in losses of 57M and 43M birds, respectively. The mandatory conversion of 66% hen inventory from conventional caged to cage-free housing by 2026 worsens the above challenges. Advised by a board of egg supply-chain stakeholders, this multidisciplinary team, with expertise in science and engineering technologies for poultry health and performance, aims to develop holistic interventions to abate diseases and heat-stress in cage-free egg housing. Our objectives are to develop integrated research, extension and education programs to: (1) engage stakeholders to assess challenges and needs in cage-free egg production; (2) develop holistic interventions to enhance bird performance and resistance to diseases; (3) develop innovative ventilation to abate heat stress and disease transmission; and (4) equip egg farmers with the knowledge and tools developed and empower future workforce via multidisciplinary education. The project outcomes include (1) new knowledge of the microbiome in cage-free housing and effective interventions to improve hen health, immunity, and performance; (2) new ventilation to abate heat stress and disease transmission; (3) translational extension programs to enable farmers to protect hen health; and (4) multidisciplinary curricula for future workforce. This project addresses the first two Program Area Priorities of the USDA AFRI IDEAS grant program: precision animal management and environmental synergies of animal production. It will contribute to healthy and sustainable egg production in the U.S.
Animal Health Component
100%
Research Effort Categories
Basic
40%
Applied
30%
Developmental
30%
Goals / Objectives
The sustainability of egg production has been challenged by significant losses caused by infectious diseases and heat stress due to frequent and intense heat waves linked to climate change. Infectious diseases have been a constant problem for the U.S. layer industry. Highly Pathogenic Avian Influenza (HPAI) is one of these airborne pathogens and has had two major outbreaks in the U.S. in the last decade alone: the 2014-2015 and 2022 outbreaks with 57 million and 57.6 million infected birds, respectively, costing the industry and taxpayers billions of dollars. In addition to HPAI, the incidence of other respiratory diseases can increase due to environmental factors leading to stress, and, consequently, immunosuppression, giving pathogens opportunities to cause diseases. Best management practices such as biosecurity, vaccinations, and chemical disinfectants have been developed and implemented to prevent outbreaks the diseases. However, while mostly effective, they cannot stop the spread of the infectious diseases because some pathogens are airborne and transmitted in airflow and into a building through the ventilation system. Hence, prevention of HPAI and other infectious diseases can only be accomplished by enhancing the general health of layers via better understanding of the environmental conditions and control strategies that prevent diseases.The mandatory conversion of 66% hen inventory from conventional caged to cage-free housing by 2026 are worsening the above challenges. Indoor environmental quality (IEQ) inside layer houses directly affects the respiratory system of layers. Elevated ammonia and dust levels have been known to enhance the incidence of respiratory diseases in caged layers. The current cage-free laying hen housing systems are 7-8 times dustier, emit higher levels of ammonia, and enrich more pathogens in comparison with the conventional caged systems. Ventilation systems play an important role to ensure the general health of layers by removing excessive heat, moisture, air pollutants, and airborne pathogens in poultry facilities. However, the typical ventilation systems adopted in current poultry houses, including cross and tunnel ventilation systems, have difficulties in limiting transmission of diseases while maintaining a comfortable and uniform thermal environment. Thus, a holistic, innovative, and forward-thinking approach is warranted for us to develop effective and proactive strategies for sustained layer health in the context of housing environment, heat stress, infectious diseases, social acceptance, productivity, as well as sustainability. The egg industry is in need of effective interventions and innovative environmental quality control technologies to sustain health and improve production efficiency.Our long-term goal is to improve hen health and performance by effective indoor environmental quality interventions and an innovative ventilation and air-conditioning system through a multidisciplinary team collaboration that converges the sciences and engineering technologies in animal health, animal production, and indoor environmental quality control.The specific objectives are:1. Utilize the established university and egg industry partnerships to reach out to cage-free egg producers to learn their management challenges and needs for research and education to improve hen health and production efficiency.The project team will work with the Egg Industry Center (EIC) and its stakeholders, including the American Egg Board (AEB), and the United Egg Producers (UEP), and the U.S. Roundtable for Sustainable Poultry & Egg (US-RSPE), to identify cage-free egg producers' challenges and education needs to improve poultry health and performance.2. Assess the impacts of cage-free housing environments on microbiota, immune development, disease susceptibility and transmission, and bird performance.Using both commercial farms and a controlled environment research farm, we will comprehensively assess the impacts of various cage-free housing environments on microbiota, immune development, disease susceptibility and transmission, and bird performance.3. Development of an Upward Airflow Displacement Ventilation (UADV) for cage-free layer housing to abate heat stress and disease transmission. Computational Fluid Dynamic (CFD) simulation will be used to modify a UADV system developed for caged housing [9] for its applications in cage-free layer houses. For extremely hot weather conditions, fresh air can be cooled using energy-efficient air conditioning (e.g. ground-coupled/geothermal systems) prior to entry into the bird occupied zone. A small prototype of the ventilation system will be built at the OSU Poultry Research Center and its capabilities on control of indoor thermal environment and disease transmission will be tested.4. Disseminate the advanced IEQ intervention strategies and technologies to the current and future egg industry workforce.We will develop (1) workshops and demonstrations for egg producers on innovative IEQ control interventions for improved health, feed efficiency, production efficiency, and sustainability; and (2) a new multidisciplinary seminar course for college students on advanced management strategies and indoor environmental control technologies to sustain poultry health and performance in the new emerging cage-free housing.
Project Methods
Objective 1. Reach out to CF egg producers to learn about their management challenges and needs for research and education programs The project team will work with the Egg Industry Center (EIC) and its stakeholders to identify the cage-free (CF)egg producers' challenges in sustain poultry health and their education needs in the challenge areas. Through the annual meetings with the stakeholder advisory board, annual EIC Industry Issue Forum, and the annual UEP meeting, the project team will exchange experiences and issues with egg producers on emerging CF housing, management challenges, and producers' needs for research and education in hen health and production efficiency.Objective 2. Assess the impacts of cage-free housing environments on microbiota, immune development, disease susceptibility and transmission, and bird performanceWe will assess the impacts of typical CF production systems on microbiota, immune development, and bird performance in commercial settings and evaluate potential impacts of key IEQ parameters on susceptibility to infectious diseases and pathogen transmission in research farms with controlled experiment.Selection of participating commercial CF layer farms. We will closely work with the stakeholder advisors to identify 3-4 typical cage-free egg farms in Ohio and/or Iowa. Each of the farm selected with be monitored for IEQ for 10 days and sampled for microbiome for three (3) days per season for two years.Monitoring indoor environmental quality (IEQ). We will conduct detailed measurements of selected IEQ parameters (air temperature, relative humidity, ammonia, and dust concentrations) in the CF housing systems. IEQ measurements and sample collection will be performed for 10 days during each season for two years. Strategic testing locations (6-10) will be determined by ventilation airflow pattern, manure management, and layout of internal equipment and/or structures used in the CF layer houses. Automatic wireless sensor networks developed in the PD's lab will be used to continuously monitor air temperature and humidity in CF hen houses [40, 41]. The air temperature, relative humidity, and air speed will also be measured using a portable TSI VelociCalc Ventilation Meter (Model 9565, TSI, Shoreview,MN). PM size-segregated mass fraction concentrations corresponding to PM1, PM2.5, respirable, PM10, and total PM will be measured by TSI Dustrak (Model 8533-Dustrak DRX, TSI Inc., Shoreview, MN). Ammonia concentration will be measured by a portable INNOVA Multi-Gas Analyzer (Model 1412, INNOVA Air Tech Instruments, Ballerup, Denmark). The equipment will be calibrated seasonally and fully disinfected every time before deployed to an egg farm.Microbial sampling at CF layer houses and lab analysis. Collaboration with farmers or farm workers will be established for microbial sampling considering biosecurity requirement. All studies involving animals will be completed under IACUC (Institutional Animal Care and Use Committee) approved protocols with institutional biosafety committee approved methods.The barn environment (dust, air, water, and manure) and the flock (10-20 birds per sampling time) will be sampled at each time point for comprehensive analysis of microbiota (through 16S and shotgun sequencing) and pathogen exposure (through established pathogen-specific PCRs and immunological assays).Microbiome level analysis will be completed with assistance from the OSU Molecular and Cellular Imaging Center via previously completed protocols involving poultry samples. Specific E. coli recovery from samples will include plating on McConkey's agar, followed by PCR of select colonies with morphology consistent with E. coli. Primers indicative of avian pathogenic E. coli.Bird immune development will be assessed by measuring stress and immunosuppression indicators such as serum corticosterone, alpha-1 glycoprotein, and peripheral blood heterophil/lymphocyte ratios, cytokine gene expression levels (in trachea, spleen and cecal tonsils), pathogen-specific serum antibody levels, and lymphocyte proliferation in response to mitogens.Measurement of bird performance. Throughout the study, feed intake, water intake and body weight will be measured. Age at first egg, egg number/hen and egg mass data will be collected to determine effects of IEQ on hen performance.Identification of causal relationships between IEQ and microbiota levels, prevalence of pathogens and bird performance. Changes in microbiota levels and prevalence of pathogens in the barn environment and within birds will be quantitatively compared with selected IEQ data to reveal possible causal relationships. The flock performance data will be compared with data from IEQ and microbiota analyses, for each type of CF production systems. Pathogens will be detected as described above and flock performance data collected from farm managers for comparison across multiple CF housing systems. Age, breed, and season will be kept as close as possible to account for the influence of these variables on performance parameters.Objective. 3 Development of an Upward Airflow Displacement Ventilation System for Cage-Free Layer Houses Design of the UADV. The UADV system developed for caged housing will be modified for applications in cage-free (CF) layer houses. Three-dimensional distributions of the indoor airflow, thermal environment, and pathogen transportation in commercial CF layer house with typical cross ventilation and UADV systems will be modelled under summer and winter conditions using CFD. ICEM CFD (ANSYS 15.0, PA, USA) will be used to create house geometry and meshing, which were imported to Fluent (ANSYS 17.0, PA, USA) for the CFD simulation. Grid independence test will be conducted to select the optimal grid size to ensure both accuracy and modeling efficiency. The boundary conditions will be configured in a similar way to those in, except that the locations of layers will be modeled with appropriate proportions between perches and floor to mimic the location of layers in actual CF layer house at a particular moment in light and dark period, respectively. Post-processing of simulation data will be focused on calculation of air-exchange effectiveness, effective temperature, and pathogen concentration at bird level.Performance evaluation of the UADV. Both the developed UADV system and the typical cross ventilation system will be tested in the research poultry experimental room at OSU Poultry Research Center. Seven poultry experimental rooms, 12'x14'x9', would be used to house CF layers and simulate the CF production systems. Every room contains independent temperature and air flow units for controlling environmental conditions, and is BSL-2 capable. Thermal environment, including air velocity, air temperature, and relative humidity at bird level will be monitored. The measurements under typical cross ventilation and UADV systems will be compared.Objective 4. Disseminate the advanced IEQ intervention strategies and technologies to the egg industry's current and future workforce. The much-needed knowledge and technologies developed in this study will be translated intoExtension trainings and publications based on stakeholder needs (Obj. 1) to support egg farmers' informed decisions in the conversion process to cage-free operation for healthy and sustainable egg production; improve extension educators' knowledge on cage-free egg production and confidence to support egg farmers; anda new multidisciplinary seminar course for college students on "Infectious Diseases in Laying Hens and Preharvest Interventions Strategies and Technologies " for the new emerging cage-free housing.