Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
Association of barn air quality parameters and lung consolidation, airway inflammation and infection in group-housed calves
Van Leenen, K.; Jouret, J.; Demeyer...
Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
Read
Respiratory disease remains an important cause of morbidity and mortality in calves and is associated with substantial antimicrobial consumption. Reduction of antimicrobial use is demanded to fight increasing antimicrobial resistance. This reduction can be achieved by improved diagnostics, prudent antimicrobial use and disease prevention. Assuring a healthy environment with adequate air quality in calf barns is a preventive measure of major importance. However, which air quality parameters are exactly associated with (sub)clinical pneumonia or airway inflammation in calves is basically unknown.
A cross-sectional study was performed to explore the associations of air quality parameters with lung consolidation, pulmonary inflammation and infection in group-housed calves. Sixty beef and dairy herds were visited from January – April 2017 and a total of 428 indoor group-housed calves was sampled. To assess barn air quality the following measurements were performed at calf breathing level: continuous 24-hour measurements of ammonia concentration, relative humidity and temperature and punctual measurements of air velocity, ammonia and CO2. Clinical examination, thoracic ultrasound and broncho-alveolar lavage for bacteriological and cytological analysis of broncho-alveolar lavage fluid (BALf) was performed. Data was analysed using multivariable mixed models and cluster analysis.
Barn temperatures showed the expected diurnal variation with an average of 14.2°C (standard deviation (SD) 4.4, range 5.5 – 23.9). Average relative humidity was 68.8% (SD 8.9, range 52.2 – 91.6). Ammonia concentrations were low with an average 24-hour concentration of 1.7 ppm (SD 0.9, range 0 – 4.0). Air velocity was variable, ranging from 0 – 2.0 m/s. This parameter was analysed as binary variable based on the optimal maximum air velocity cut-off value to detect a lung consolidation of ≥1 cm in depth, which was 0.8 m/s. Lung consolidations of ≥1 cm, ≥3 cm and ≥6 cm in depth were present in 41.1% (176/428), 27.1% (116/428) and 16.1% (69/428) of the calves, respectively. Lung consolidations of all depths were positively associated with mean or maximum temperature. Ammonia exposure, in hours ≥4 ppm, was associated with lung consolidation ≥1 cm (odds ratio (OR) = 1.73; con- fidence interval (CI) = 1.02 – 3.07; P = 0.04). The epithelial cell percentage in BALf was also positively associated with ammonia concentration (P = 0.01). The odds of lung consolidation ≥3 cm (OR = 7.7; CI = 1.35 – 41.7; P = 0.02) and ≥6 cm (OR = 25.0; CI = 2.5 – 33.3; P = 0.007) increased with air velocity >0.8 m/s.
Cluster analysis, based on average pen temperature and relative humidity, maximal air velocity, NH3 and CO2 concentration and bacterial air load, resulted in four different barn climate clusters. Cluster 1 was characterised by a warm and dry climate with ammonia accumulation (n = 19). Cluster 2 represented under-ventilated barns with accumulation of air pollutants (NH3, CO2) and high bacterial air load (n = 8). Cluster 3 was labelled as a presumably normal climate based on low concentrations of air pollutants and average temperature and relative humidity values, combined with low air velocity (n =25).Cluster 4 was labelled as the draught cluster, characterised by high air velocity (n = 3). In cluster 4, the draught cluster, the prevalence of lung consolidations ≥1 cm was higher (81.8%; P < 0.001) compared to the presumably normal cluster (31.6%). Also, in the warm, dry and ammonia accumulation cluster the prevalence of these consolidations was higher (54.2%; P = 0.02) compared to the normal cluster. Furthermore, in the warm, dry and ammonia cluster the prevalence of consolidations ≥3 cm (38.1%; P = 0.04) and ≥6 cm (31.4%; P = 0.01) were higher compared to the presumably normal climate cluster (18.2% and 9.1%, respectively).
Average and maximum temperature, ammonia concentration and air velocity are associated with pneumonia in group- housed calves and therefore seem to be the most valuable parameters to measure when evaluating barn climate. Cluster analysis using different parameters can aid in identification of calf barns with sufficient air quality and further improve our understanding of calf barn climatic conditions.
Keywords: Temperature, ammonia, air velocity, thoracic ultrasonography, broncho-alveolar lavage fluid.
Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
About
Affiliation of the authors at the time of publication
Ghent University, Merelbeke, Belgium;
Belgian Center for Occupational Hygiene, Zwijnaarde, Belgium;
Flanders Research Institute for Agriculture, Fisheries and Food, Merelbeke, Belgium.
Comments (0)
Ask the author
0 comments