Conglutinin and immunoconglutinin titers in stressed calves in a feedlot

Objective-To determine whether increased conglutinin titers are evident in stressed calves that do not develop respiratory tract disease in feedlots,c ompared with respiratory tract disease, and to determine the increase in im munoconglutinin titers. Animals-101 mixed-breed beef calves. Procedure-Calves were processed at 4 farms of origin and allowed to remain with their dams for another 100 days. Calves from each farm were brought to a centrally located order-buyer barn. In a feedlot, 101 calves were assign ed to pens and observed daily for clinical signs of acute respiratory tract disease. When sick carves were detected, they were treated with antibiotic s and isolated in a pen for 4 days. Conglutinin and immunoconglutinin titer s were determined for all calves. Results-During the 28-day study, 73 calves developed respiratory tract dise ase, whereas 28 calves remained healthy. Mean conglutinin titers differed s ignificantly among carves from the 4 farms. Significant differences were no t detected in conglutinin titers among calves on the basis of sex, morbidit y, or vaccination status against Mannheimia haemolytica at each farm, the o rder-buyer barn, or the feedlot on days 8, 15, and 28 after arrival. Immuno conglutinin titers in calves differed significantly among farms and morbidi ty status. Conclusions and Clinical Relevance-Mean conglutinin titers in calves do not appear to be associated with the incidence of acute respiratory tract dise ase; however, increased immunoconglutinin titers appear to be associated wi th recovery of stressed calves from respiratory tract disease during the fi rst 15 days after arrival in a feedlot.