Summary
This longitudinal study tracked the natural carriage dynamics of three bovine respiratory pathobionts in 60 healthy beef calves housed over winter, revealing species-specific patterns in colonisation and clearance. Using quantitative PCR, the authors found that P. multocida and H. somni exhibited median carriage durations of 55.5 and 14.8 days respectively, with higher P. multocida density associated with slower bacterial clearance. The findings provide empirical data on pathobiont dynamics in cattle and establish a methodological platform for further longitudinal and modelling studies in this domain.
UK applicability
The study was conducted in a United Kingdom experimental farm setting and directly reflects UK winter housing conditions for beef cattle. The findings are therefore directly applicable to UK beef production systems and may inform understanding of respiratory disease epidemiology and pathobiont ecology in similar UK farming contexts.
Key measures
Carriage rates (percentage of animals positive); bacterial density (quantified by qPCR); median duration of carriage with 95% confidence intervals; association between bacterial density and clearance time (p-value)
Outcomes reported
The study quantified carriage rates and density of three bovine respiratory pathobionts (Pasteurella multocida, Histophilus somni, and Mannheimia haemolytica) in nasal passages of healthy beef calves over a 75-day winter housing period using qPCR. Median carriage durations and associations between bacterial density and clearance rates were estimated using interval-censored exponential survival models.
Topic tags
Dig deeper with Pulse AI.
Pulse AI has read the whole catalogue. Ask about this record, its theme, or how the findings apply to UK farming and policy — every answer cites the underlying studies.