Understanding metaphylaxis practices for cattle at uncertain risk for bovine respiratory disease across U.S. feedlots: a survey of veterinarians and feedlot managers.

Bovine respiratory disease (BRD) is the most frequent and costly disease in U.S. feedlots. Metaphylactic antimicrobial use effectively reduces morbidity and mortality in cattle at high risk of BRD, however, its implementation is challenging when risk classification is unclear, and the cost-benefit is uncertain. This study aimed to collect and analyze input from feedlot managers and veterinarians on the criteria used to administer metaphylaxis on cattle of uncertain, or "medium" BRD risk. Responses from 25 veterinarians consulting for 617 feedlots (80 to 120,000 animal capacity) across 32 states, and 30 managers overseeing feedlots across 12 states (500 to 120,000 animal capacity) were analyzed. Nearly half of veterinarians (48%) expected BRD morbidity of 15% to 20% and mortality of 2% to 3% in cattle at medium-risk, whereas only about 15% of managers shared these same expectations. Manager expectations varied widely, with 55% anticipating morbidity of 5% to 15% and no clear consensus on expected mortality. Veterinarians most frequently identified cattle history (64%), weight (59%), commingling (50%), transportation time (50%), and weather (50%) as the primary criteria for determining the need for metaphylaxis in cattle at medium BRD risk. Managers cited similar factors but most often reported source (45%) and origin (35%) as key considerations, with less frequent mentions of weather (14%) and weight (28%). Before cattle arrived at the feedlot, "market channel" was the most influential factor for considering metaphylaxis use according to both veterinarians (73%) and managers (82%), whereas after cattle arrival, "overall cattle health condition" was the most cited factor (69% of veterinarians and 75% of managers). By contrasting the perspectives of veterinary consultants and feedlot managers, we identified consistencies and discrepancies in their perceptions, information use, and the challenges associated with metaphylaxis decisions for these cattle cohorts. These findings contribute to a better understanding of the information that feedlot professionals use and need to guide metaphylaxis decisions in cattle at uncertain BRD risk, thereby supporting efforts toward antimicrobial stewardship and sustainable beef production.