Dr. Amit Kumar Pandey
B.V.Sc., Ph.D. (VPT).
“More than 90% of lung diseases are either initiated by or at least aggravated by inhalation of particles and gases”.
Particulate matter (PM) stands out as a significant environmental stressor within the global poultry industry. Its extensive specific surface area enables the absorption and transportation of various pollutants, encompassing heavy metal ions, ammonia, and persistent organic pollutants like pathogenic microorganisms. More than 90% of lung diseases are either initiated by or at least aggravated by inhalation of particles and gases. The influence of particulate matter (PM) on the initiation or exacerbation of lung diseases is progressively gaining recognition. Owing to inherent constraints in the rearing environment, the composition of air within poultry houses significantly deviates from the atmospheric norm. The production process, along with factors such as feed, faeces, feathers, and dander, contributes substantially to the production of considerable volumes of PM, posing challenges in effective mitigation.
Fig: Composition, sources, and sizes of particulate matter (PM) in the poultry houses and their impact on the respiratory tract.
Due to the diverse origins of particulate matter (PM) and their temporal and spatial fluctuations, there can be notable variations in the composition and concentration of PM. Within poultry houses, the concentration of PM was observed to be approximately 10 to 100 times higher in confined spaces compared to outdoor environments. Particulate matter with a particle size less than 10 μm (PM 10) has the capability to reach the upper respiratory tract of broilers, while PM with a particle size less than 2.5 μm(PM 2.5) can enter the broiler’s lungs, reaching to the alveoli and triggering an inflammatory response. Additionally, under conditions of elevated temperatures and humidity, there is a greater likelihood for substantial amounts of microorganisms, secondary particles, and toxic compounds produced during amino acid metabolism in the animal digestive system to adhere to the PM.
Bird’s lungs are more susceptible:
In contrast to mammalian lungs, broilers contain multiple bronchi and air sacs. The unique structure places the broiler’s lung in a semi-open state and, thereby, more susceptible to PM damage. Due to the heterogeneity of PM, long-term exposure to high PM concentrations can make broilers susceptible to different respiratory diseases.
Sources, chemical composition, and influencing factors of Particulate (PM) matter in poultry houses.
PM found in poultry houses predominantly comprises primary particles with biological origins, including fungi, bacteria, viruses, endotoxins, and allergens. Additionally, particles originating from feed, skin, and faeces contribute to the overall composition. Within poultry houses, primary PM sources include poultry feathers, mineral crystals in urine, and waste materials. Notably, bedding emerges as a substantial source of PM, particularly in litter-fed poultry houses compared to litter-free counterparts. The elemental composition of PM in poultry houses encompasses C, O, N, P, S, Na, Ca, Al, Mg, and K. Furthermore, variations exist in the elemental components present in PM2.5 (aerodynamic diameter < 2.5 μm) and PM10 (aerodynamic diameter < 10 μm) across different origins within broiler houses.
Respiratory health hazards of particulate matter (PM) in poultry house
PM in poultry houses affects respiratory health mainly in 3 ways:
- Inhaled PM irritates the respiratory tract, decreases immune resistance, and causes respiratory disease.
- Irritation of the respiratory tract by compounds presents in PM.
- Respiratory diseases are caused by infections with pathogenic and non-pathogenic microorganisms attached to PM.
Ammonia in Poultry House PM Poses a Respiratory Health Hazard
Ammonia stands out as the most alkaline and detrimental irritant gas present in poultry houses. The incorporation of airborne ions and volatile particles originating from ammonia crystals in urine constitutes a crucial element of PM2.5 within these facilities. Given the reduced frequency of ventilation during the winter season, the prevalence of a heightened concentration of ammonia is a common occurrence in intensive poultry houses. It is widely acknowledged that the absorption of exogenous ammonia in poultry primarily instigates the breakdown of mucosal barriers in the respiratory tract and lungs, resulting in an immune imbalance and fostering the development of respiratory inflammation. Prolonged exposure of broilers to ammonia has been associated with a significant increase in inflammatory markers, activation of the nuclear transcription factors κB (NFκB) pathway, apoptosis, and disruptions in the immune status within the trachea.
Microorganisms in Poultry Houses Pose a Respiratory Health Hazard
Particulate matter (PM) acts as a carrier for pathogenic bacteria, endotoxins, and allergens, often contributing to respiratory diseases, such as chronic bronchitis, asthma, and dust poisoning syndrome.
Within poultry houses, bacterial threats to poultry health include Chlamydia spp., Staphylococcus aureus, Listeria spp., Streptococcus spp., and various Salmonella spp. These bacteria have the potential to infect the respiratory and lung systems, resulting in interstitial pneumonia, airway inflammation, and a spectrum of respiratory diseases.
Fungal species like Aspergillus, Scopulariopsis, Wallemia, and Fusarium are prevalent in poultry house PM. These fungi originate from plant raw materials and feces. Given that fungal spores can easily reach the lower respiratory tract when carried by PM, they have the potential to induce allergic reactions, respiratory inflammation, and pneumonia.
II. Prevention and management Strategies to reduce PM in poultry houses.
Dust Control Measures: Implementing effective dust control measures is crucial. This includes regular cleaning and removal of accumulated dust, using dust-binding agents on litter, and optimizing ventilation systems to minimize airborne particles.
Ventilation System Optimization: Upgrading ventilation systems with advanced technologies ensures efficient removal of particulate matter from the air. Enhanced airflow patterns, air filtration, and regular maintenance contribute to improved air quality.
Litter Management: Proper litter management is essential for reducing the release of particulate matter. Regularly changing and treating litter, along with maintaining appropriate moisture levels, can minimize dust production.
Air Filtration Systems: Installing air filtration systems can effectively capture and remove airborne particulate matter. High-efficiency particulate air (HEPA) filters and electrostatic precipitators are examples of technologies that can enhance air quality.
Moisture Control: Controlling humidity levels in poultry houses is crucial to preventing the formation of dust. Humidity management practices, such as using proper ventilation and litter treatments, contribute to reducing airborne particles.
Nutritional Intervention: Including additives in poultry feed, such as natural binders, antioxidants and herbal respiratory stimulants can mitigate the impact of particulate matter on respiratory health. These additives may reduce inflammation and enhance the birds’ respiratory resilience.
Particulate Matter in poultry houses poses a significant risk to respiratory health, demanding advanced preventive measures for optimal flock performance. By understanding the sources and composition of PM, poultry producers can implement a holistic approach that integrates dust control, ventilation optimization, litter management, and innovative technologies. As the poultry industry continues to evolve, a commitment to maintaining clean and healthy air in poultry houses is paramount, ensuring the well-being of the flock and sustaining the industry’s overall success.