Longitudinal assessment of the Fusobacterium necrophorum and Fusobacterium varium in the nasal cavity of finishing beef steers with and without liver abscesses

Authors: DORNBACH, COLTEN - Texas Tech University; Broadway, Paul; CHILDRESS, KALLIE - Texas Tech University; THOMPSON-SMITH, AUBREY - Texas Tech University; CANTERBURY, LANDON - Texas Tech University; Sanchez, Nicole; AMACHAWADI, RAGHAVENDRA - Kansas State University; NAGARAJA, T - Kansas State University; GALYEAN, MICHAEL - Texas Tech University; HALES, KRISTIN - Texas Tech University

Submitted to: Applied Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2025
Publication Date: 10/1/2025
Citation: Dornbach, C.W., Broadway, P.R., Childress, K.D., Thompson-Smith, A.C., Canterbury, L.G., Sanchez, N.C., Amachawadi, R.G., Nagaraja, T.G., Galyean, M.L., Hales, K.E. 2025. Longitudinal assessment of the Fusobacterium necrophorum and Fusobacterium varium in the nasal cavity of finishing beef steers with and without liver abscesses. Applied Animal Science. 16. https://doi.org/10.3389/fmicb.2025.1565303.
DOI: https://doi.org/10.3389/fmicb.2025.1565303

Interpretive Summary: Liver abscesses are of major economic concern for the cattle industry. Decreased live and carcass performance from liver abscesses lead to a $1 billion annual loss. Fusobacterium necrophorum is the most common bacteria found in liver abscesses. Fusobacterium has also been found in the respiratory tract. It was hypothesized that Fusobacterium in the nasal cavity could be indicative of liver abscess formation. A study was conducted by scientists in Lubbock, TX and university collaborators using beef steers. Nasal swabs from steers with and without a liver abscess were tested for Fusobacterium. Fusobacterium was found in the nasal cavity, but there was no link between this bacteria and liver abscesses. Future research is needed to evaluate links between Fusobacterium in the respiratory tract with bovine respiratory disease and liver abscess formation. These data will be of interest to scientists in the field of cattle health and performance and beef producers.

Technical Abstract: We longitudinally assessed the prevalence of F. necrophorum subsp. necrophorum, F. necrophorum subsp. funduliforme, and F. varium in the nasal cavity of finishing beef steers with and without liver abscesses (LA). Crossbred beef steers (n = 225; arrival BW = 353 kg ± 39.6 kg) were transported to a feedlot and used a case-control design. From d 0 to study end, steers were fed a high-concentrate diet. Nasal samples were aseptically collected after feedlot arrival (d 5), one week after adaptation to the finishing diet (d 35), and the day before harvest (study end). Livers were collected at harvest and examined for LA, and cattle were subsequently assigned into either case (LA present) or control (LA not present) groups. Nasal samples from cattle with a LA (n = 42), as well as nasal samples from a cohort of healthy steers without LA (n = 42) were selected for Fusobacterium analysis. The GLIMMIX and MIXED procedures of SAS 9.4 were used to evaluate binomial and continuous data, respectively, with fixed effects of treatment, sampling time, and treatment × sampling time interaction. Overall LA prevalence was 18.7%. Nasal concentration and prevalence of F. necrophorum subsp. necrophorum (P = 0.82) and F. varium (P = 0.54) did not differ between steers with or without a LA or across sampling period (P = 0.36). Likewise, nasal concentrations of F. necrophorum subsp. funduliforme did not differ between steers with or without a LA (P = 0.58), but nasal F. necrophorum subsp. funduliforme prevalence exhibited a treatment × sampling interaction (P = 0.03), with prevalence being lower in steers with a LA on d 35 than in those without a LA. The etiology of LA development remains unresolved, and these data are the first report of Fusobacterium isolation from the nasal cavity of feedlot beef steers. Although these data suggest that Fusobacterium are present in the nasal cavity of finishing beef steers throughout the feedlot period, a direct link between nasal Fusobacterium concentrations and LA development was not detected. Future research is needed to further evaluate relationships between Fusobacterium populations in the respiratory tract, BRD prevalence, and LA formation.