A Stochastic model designed to estimate variability in the relative economic value betweem cattle with and without lung lesions in U.S. feedlot production systems

Feedlot cattle with lung lesions, associated with bovine respiratory disease (BRD], display a reduction in average daily gain (ADG) compared to cattle without lung lesions. However, a moderate degree of variability in prevalence and ADG reduction has been observed in peer-reviewed literature; therefore, the true economic impact of lung lesions in feedlot cattle populations is unknown. The study objective was to estimate and compare the relative economic value between feedlot cattle with and without lung lesions through stochastic modeling methods. The model commenced at animal purchase and upon pen placement. Within each pen, cattle with and without lung lesions were modeled in parallel throughout the feeding phase, incorporating all production expenses and revenue. The final outcome was the difference in economic value between both cohorts when marketed on a live-weight basis. Based upon the assumption of this model, cattle with lung lesions lose, on average, $38.69 (90% probability interval: $12.28 to $79.32] compared to cattle without lung lesions. The reduction in ADG among cattle with lung lesions was a major driver in these outcomes supporting the findings from prior studies. Improved BRD diagnostic and therapeutic modalities are necessary to reduce lung lesion prevalence and subsequent negative economic impacts to the feedlot industry.