Qualification and Quantification of Bacterial Pathogen Load in Acute Bovine Respiratory Disease Cases

In December 2009 a total 194 steers, bulls, and heifers weighing 400-700 lb (180-320 kg) were purchased at an Arkansas sale barn on a Friday and shipped 12 hours to a northern Kansas feedlot on Saturday. There was no previous history of treatment. The objectives of the study were to evaluate (1) bacterial pathogen isolates in different locations in the respiratory tract, (2) pathogen load in lung tissue as it corresponds to histology scores, and (3) total pathogen load in clinically ill and clinically normal calves.
American Association of Bovine Practitioners Proceedings of the Annual Conference, 2010