Respiratory pathogens in veal calves: Inventory of circulating pathogens

Area of Science:

• Veterinary Medicine
• Animal Health
• Microbiology

Background:

• Bovine respiratory disease (BRD) significantly impacts veal calf health and welfare in The Netherlands.
• High antimicrobial usage in veal production necessitates targeted treatment strategies.
• Identifying causative agents of BRD is crucial for reducing antimicrobial consumption.

Purpose of the Study:

• To determine associations between specific pathogens and clinical BRD in veal calves.
• To investigate the relationship between pathogen prevalence and BRD outbreaks.
• To explore the impact of BRD on calf performance metrics.

Main Methods:

• A 12-week cohort study was conducted on ten veal farms.
• Broncho-alveolar lavage samples were collected from diseased and control calves during BRD outbreaks.
• A wide range of microorganisms were isolated, and performance data were recorded.

Main Results:

• Twenty-three BRD outbreaks occurred, primarily in the first six weeks.
• Trueperella pyogenes, Mycoplasma bovis, and Bovine viral diarrhea virus (BVDV) showed significant associations with diseased calves.
• Bovine parainfluenza virus 3 (BPI3V) was detected in early outbreaks, suggesting a potential role.

Conclusions:

• Establishing direct links between specific pathogens and BRD outbreaks at the species level remains challenging.
• BRD is a primary driver for antimicrobial treatments in veal calves.
• Enhanced understanding of pathogen-disease associations is vital for optimizing antimicrobial stewardship in veal production.