Control of liver abscesses in feedlot cattle: A review1

Published literature was reviewed to provide an overview of the historical prevalence and methods of controlling liver abscesses (LA) in feedlot cattle. Liver abscesses are typically categorized as mild, moderate, or severe, with severe LA most often being associated with reductions in performance. The prevalence of LA in beef-breed steers increased by 25% between 2008 and 2013; however, the prevalence in Holstein steers tripled over the same period. Regionally, the greatest prevalence has been observed in Kansas, eastern Colorado, and western Nebraska, and the lowest prevalence has been observed in the Midwest and the desert southwest. Fusobacterium necrophorum and Trueperella pyogenes are most commonly associated with LA, although F. necrophorum is likely the primary causative pathogen. Liver abscesses are often, but not always, associated with perforations in the rumen wall. Tylosin phosphate is commonly fed to control LA. Feeding elevated levels of roughage during growing and finishing periods results in a dramatic reduction in LA; overprocessing of dietary roughage reduces its effectiveness. Grain processing has marked effects on ruminal starch availability but has minimal effect on LA; inclusion of fibrous by-product feeds also does not mitigate prevalence of LA. Vaccination against F. necrophorum has shown little benefit in field application. Providing a source of true scratch-factor to the rumen, either by increasing the percentage of coarse roughage included in the TMR or by periodically providing coarse hay apart from the TMR, appears to be the most effective method of reducing LA.