Abstract
Liver abscesses (LA) cause significant economic losses in U.S. beef feedlot cattle through a variety of production and performance effects. This research estimated annual economic losses secondary to LA in U.S. beef feedlot cattle using a stochastic simulation model that was based on data from the literature, economic data, and expert opinion. LA prevalence was estimated for 4 U.S. regions and 4 cattle types along with their combinations. Economic losses were estimated by combining modeling results from individual loss categories related to feed efficiency, liver, offal, and trim loss, effects on carcass quality, and processing delays. Losses were also estimated under different antimicrobial use and production scenarios. We estimated that LA result in annual losses of $256M (95% Credible interval: $162M to $378M) to the U.S. beef industry. Decreased average daily gain (ADG) and a lower dressing percentage prior to trimming accounted for nearly half (48.6%) of these losses, while liver and offal condemnation and excess trimming comprised approximately 40% of all losses. Processing delays were estimated to contribute approximately 5% of the total losses. There was also substantial variation in the estimated prevalence and impacts of LA by region and cattle type, with beef-dairy crossbred (BD) cattle in the Western region experiencing the highest economic losses per animal. Scenario analyses predicted that eliminating the use of tylosin may nearly double LA prevalence and associated economic costs while transitioning all beef cattle born on dairies from Holsteins to BD cattle would only slightly increase overall losses. Our findings show that LA cause substantial, yet uncertain, losses to the U.S. beef feedlot industry. The results also emphasize the need for additional research to elucidate the effect of LA on feed efficiency and to improve LA prevention strategies, which could enhance animal health and productivity as well as industry sustainability.