Despite the development of new vaccines, and therapeutics, bovine respiratory disease (BRD) continues to be the primary health problem of feedlot cattle. Assessment of the entire feeding performance loss associated with BRD has not been studied. The Texas Ranch to Rail program includes the entire feeding disease loss. Their findings will be reviewed. Intervention of BRD includes the use of vaccines and timely therapeutics. Effort is given in feedlots to have properly trained employees daily evaluate the health of cattle in the belief that well timed therapy will alter the course of BRD. This paper will review two research projects designed to evaluate BRD intervention in ranch fresh weaning calves.