Bovine Respiratory Microbiome and Welfare: Emerging Science

The respiratory microbiome of cattle is emerging as a key factor in bovine respiratory disease (BRD) susceptibility and welfare. Understanding the microbiome opens new approaches to prevention.

Key Facts

BRD is the leading cause of morbidity and mortality in feedlot cattle and a major welfare and economic burden
The respiratory microbiome includes commensal bacteria that compete with pathogens for colonisation sites
Metaphylaxis (mass antibiotic treatment at feedlot entry) disrupts the microbiome and may increase long-term susceptibility
Probiotic and prebiotic interventions targeting the respiratory microbiome are under active research

Welfare Considerations

Respiratory disease causes significant suffering — affected cattle show fever, purulent nasal discharge, laboured breathing, and severe depression. The microbiome perspective shifts the focus from pathogen control to resilience building — maintaining a diverse, commensal-dominated respiratory flora that resists pathogen colonisation. Reducing stress events that suppress immunity and disrupt the microbiome (transport, mixing, weather extremes) is the most impactful welfare-positive prevention strategy.

What You Can Do

Support research into bovine respiratory microbiome interventions as alternatives to prophylactic antibiotics
Advocate for reduced mass medication in feedlot systems in favour of targeted treatment and prevention
Choose beef products from systems that report antibiotic use data and demonstrate reduction programs
Encourage veterinary advisory services to incorporate microbiome health into cattle health management planning