Bovine respiratory disease is the most costly and welfare-significant disease syndrome in beef cattle, causing significant morbidity and mortality particularly in newly weaned and transported calves.
BRD welfare harm is both acute and potentially chronic for cases that develop into severe pneumonia or chronic respiratory compromise. The disease is inherently linked to the stressors of modern beef production - weaning stress, transport stress, and social mixing all compromise immunity and increase susceptibility. Management approaches that reduce these stressors - pre-conditioning calves to feedlot feeding before weaning, minimizing transport duration, maintaining stable social groups at arrival - reduce BRD incidence and associated welfare harm. Metaphylactic antibiotic treatment of entire groups at high BRD risk, while effective, represents a welfare-and-antibiotic-stewardship tension that is driving interest in stress reduction alternatives.