Particulate matter and airborne endotoxin concentration in calf barns and their association with lung consolidation, inflammation, and infection

Abstract

Agricultural operations are important sources of organic dust containing particulate matter (PM) and endotoxins, which have possible negative health consequences for both humans and animals. Dust concentrations and composition in calf barns, as well as the potential health effects for these animals, are scarcely documented. The objective of this study was to measure PM fractions and endotoxin concentrations in calf barns and study their associations with lung consolidation, respiratory tract inflammation, and infection in group-housed calves. In this cross-sectional study, samples from 24 dairy farms and 23 beef farms were collected in Belgium from January to April 2017. PM 1.0 , PM 2.5 and PM 10 (defined as particulate matter passing through a size-selective inlet with a 50% efficiency cutoff at a 1.0-μm, 2.5-μm, and 10-μm aerodynamic diameter, respectively) were sampled during a 24-h period using a Grimm aerosol spectrometer (Grimm Aerosol Technik Ainring GmbH & Co. KG). Endotoxin concentration was measured in the PM 10 fraction. Thoracic ultrasonography was performed and broncho-alveolar lavage fluid was collected for cytology and bacteriology. Average PM concentrations were 16.3 μg/m 3 (standard deviation, SD: 17.1; range: 0.20-771), 25.0 μg/m 3 (SD: 25.3; range: 0.50-144.9), and 70.3 μg/m 3 (SD: 54.5; range: 1.6-251.2) for PM 1.0 , PM 2.5 , and PM 10 , respectively. Mean endotoxin in the PM 10 fraction was 4.2 endotoxin units (EU)/μg (SD: 5.50; range: 0.03-30.3). Concentrations in air were 205.7 EU/m 3 (SD: 197.5; range: 2.32-901.0). Lung consolidations with a depth of ≥1, ≥3, and ≥6 cm were present in 43.1% (146/339), 27.4% (93/339), and 15.3% (52/339) of the calves, respectively. Exposure to fine (PM 1.0 ) PM fractions was associated with increased odds of lung consolidations of ≥1 cm (odds ratio, OR: 3.3; confidence interval (CI): 1.5-7.1), ≥3 cm (OR: 2.8; CI: 1.2-7.1), and ≥6 cm (OR: 12.3; CI: 1.2-125.0). The odds of having lung consolidations of ≥1 cm (OR: 13.9; CI: 3.4-58.8) and ≥3 cm (OR: 6.7; 1.7-27.0) were higher when endotoxin concentrations in the dust mass exceeded 8.5 EU/μg. Broncho-alveolar lavage fluid neutrophil percentage was positively associated with PM 10 concentration, and epithelial cell percentage was negatively associated with this fraction. Concentration of PM 2.5 was positively associated with epithelial cell percentage and isolation of Pasteurella multocida. Although concentrations of fine dust are lower in calf barns than in poultry and pig housings, in this study they were associated with pneumonia in calves. Dust control strategies for reducing fine dust fractions in calf barns may benefit human and animal respiratory health.

Assessment of animal diseases caused by bacteria resistant to antimicrobials: cattle

“…transport, commingling, feed and water deprival, dehorning). Beside clinical outbreaks, a substantial number of calves also suffers from subclinical pneumonia (van Leenen et al, 2020(van Leenen et al, , 2021. In addition, sporadic cases in adult animals have also been described (Dorso et al, 2021).…”

Ameliorative Effect of Citrus junos Tanaka Waste (By-Product) Water Extract on Particulate Matter 10-Induced Lung Damage

“…Several studies have reported that PM10 contains endotoxins that act as LPS stimuli to induce inflammation [ 42 , 43 ]. In addition, the activation of macrophages by endotoxins (i.e., LPS) is a major inflammatory induction mechanism [ 44 ].…”

“…In addition, the activation of macrophages by endotoxins (i.e., LPS) is a major inflammatory induction mechanism [ 44 ]. Notably, NO plays a key role in inflammatory responses, and cytokine-activated macrophages trigger NO release [ 43 ]. In this study, the CJB extract treatment decreased NO production in the RAW264.7 mouse macrophages in LPS induction ( Figure 6 b).…”

Invited review: Bovine neonatal morbidity and mortality—Causes, risk factors, incidences, sequelae and prevention

“…Given that RIs transmit primarily via the airborne route, the risk factors associated with RIs are those influencing airborne transmission such as air pathogen concentrations (Lago et al, 2006), air endotoxin and particulate matter concentrations (van Leenen et al, 2021), sharing air space with older cattle (Medrano‐Galarza et al, 2018), pen stocking rate (Svensson & Liberg, 2006) and calf housing design (Gorden & Plummer, 2010). Additionally, as with most neonatal infectious diseases, FPT is a risk factor for RI (Deepak et al, 2021) as is co‐infection with multiple respiratory pathogens (Deepak et al, 2021) and co‐morbidity with GI infections (Lorenz et al, 2021).…”