| Bovine respiratory disease complex (BRDC) poses major economic and health challenges for the beef industry. Intervention strategies abound for controlling BRDC, however before we can prevent BRDC we must understand biological risk relationships for BRDC and pulmonary lesions. Identification of risk factors for clinical BRDC and pulmonary lesions at harvest, along with determination of associations between these events, will allow development of risk assessments to decrease BRDC incidence and severity.; A Nebraska ranch, which retained ownership of steers through harvest, was used to identify associations between standard cow-calf production parameters and pulmonary lesions evident at harvest. Dam frame, dam BCS, and dam BCS*dam frame were the only significant cow-calf parameters in determining risk of calves developing pulmonary lesions, Perhaps, typically measured cow-calf management practices do not influence pulmonary lesions or inappropriate risk factors were measured.; Two data sets were used to analyze associations between cattle removed for BRDC and pulmonary lesions. Pen-level correlation coefficients between calves removed for BRDC and pulmonary lesions were of different magnitude and direction for each data set (-0.28 vs. 0.08), however non-significant. Bodyweight, upon arrival at feedyard, interacted with removal for BRDC. Relative risks, calculated by 22.7 kg increments, for calves to be removed for BRDC and subsequently have pulmonary lesions were 0.5--2.0 and 0.6--1.2 for Data Sets A and B, respectively. The variability of relative risks demonstrates an inconsistent association between calves removed from for BRDC and calves with pulmonary lesions evident at harvest.; Risk assessment would be ideal for determining economic viability of various management interventions concerning BRDC. First, we must identify risk factors of BRDC and pulmonary lesions, along with determining associations between these variables. Currently, we do not biologically understand these risks or their associations. Applying this methodology to a similar feedyard decision and economically evaluating multiple management interventions illustrated advantages of risk assessment. |
