How Much Does BRD Reduce Growth
among Preweaned Calves?
A research team examined a population of calves that after an initial period of being raised in individual pens were moved to an automatic calf feeder barn. In this barn they used thoracic ultrasonongraphy (TUS) for diagnosis with a positive case defined as the presence of consolidated lung tissue greater than or equal to 1 square centimeter.
Average daily gain data were also collected for calves at 50 days of age. Positive BRD calves averaged 730gm/day compared to negative BRD calves at 840gm/day [1.6#/day vs. 1.85#/day]. In other words, health calves gain at a rate 12 percent higher than BRD positive calves.
Note that even the calves growing at the lower rate still doubled their weight in the first two months of life.
Reference: Cramer, M.C. and T.L. Olivett, " Growth of preweaned, group-housed dairy calves diagnosed with respiratory disease using clinical respiratory scoring and thoracic ultrasound - A cohort study." Journal of Dairy Science 102:4322-4331 July 2019