BRD (shipping fever, pneumonia) affects an estimated 15-45% of feedlot cattle globally. It involves complex interactions between stress, viral pathogens (BRSV, BVD, IBR), and bacterial pathogens (Mannheimia, Pasteurella). Early-arriving feedlot cattle are most vulnerable.
BRD causes fever, painful inflammation of lung tissue, labored breathing, depression, and reduced feed intake. Chronic BRD survivors have persistent lung damage that compromises welfare and performance. Mortality rates of 1-3% represent thousands of individual animals suffering preventable deaths.
The stress of weaning, transport, commingling, and environmental change suppresses immunity, enabling pathogen colonization. Welfare-focused management reduces stressors: pre-conditioning calves before weaning, limiting transport duration, providing shelter and water promptly on arrival.
Pre-conditioning vaccination (4-6 weeks before transport) allows immune response development before stress exposure. Vaccines targeting BRSV, BVD, IBR, and bacterial antigens are most effective when given with adequate time. Metaphylaxis (mass treatment on arrival) is common but raises antimicrobial stewardship concerns.
BRD is most treatable in early stages. Trained pen riders assess cattle daily for depression, nasal/ocular discharge, and respiratory rate. Accelerometer-based health monitoring systems detect reduced movement and feeding behavior before clinical signs. Early treatment reduces suffering duration and antibiotic use.
Effective antibiotic therapy (florfenicol, tulathromycin, enrofloxacin) resolves most early-stage BRD rapidly. NSAIDs given alongside antibiotics reduce fever and pain, improving welfare and recovery speed. Retreatment criteria and veterinary protocols guide responsible antibiotic use.