A Comparison of two vaccines to reduce liver abscesses in natural-fed beef cattle

Abstract

A blinded interventional clinical trial was conducted to evaluate the efficacy of two liver abscess vaccines in natural-fed beef cattle. Feedlot cattle (n=1,307 head, initial body weight=613±71 lb; or 279±32 kg) were randomly assigned to one of three vaccine treatments: no vaccine (control); vaccination with a Fusobacterium necrophorum bacterin (Fusogard?, Novartis Animal Health US, Inc, Greensboro, NC); or vaccination with an Arcanobacterium pyogenes-Fusobacterium necrophorum toxoid (Centurion^TM, Intervet/Schering-Plough Animal Health, DeSoto, KS). Cattle were fed a finishing diet consisting of 73% steam-flaked corn arid 13% roughage (as-fed basis). At harvest, livers were scored using the Elanco Liver Scoring System. Incidence of liver abscesses (56%) and severe liver abscesses (39%) was relatively high in this study. Vaccine treatment did not affect incidence of liver abscesses or severe liver abscesses, nor did it affect liver abscess score. Initial body weight, 60-day body weight, 60-day average daily gain (ADG), total days-on-feed (DOF), hot carcass weight, yield grade, and quality grade were not different among vaccine treatments. Cattle with abscessed livers at harvest tended to have lower 60-day ADG than those without abscesses. Presence of liver abscesses increased (P=0.02) total DOF, but only by two days. Presence of severe liver abscesses was associated with reduced (P<0.01) hot carcass weight, and more cattle that graded USDA Select rather than USDA Choice (P=0.01).