Evaluating the effects of acidosis and bacterial concentrations on the development of liver abscesses in beef steers

Authors: CHILDRESS, KALLIE - Texas Tech University; HALES, KRISTIN - Texas Tech University; NAGARAJA, T - Kansas State University; LAWRENCE, TY - West Texas A & M University; AMACHAWADI, RAGHAVENDRA - Kansas State University; Sanchez, Nicole; MCDANIEL, ZACH - Texas Tech University; LINE, DALTON - Texas Tech University; THOMPSON-SMITH, AUBREY - Texas Tech University; ABBASI, MINA - Kansas State University; SHI, XIARONG - Kansas State University; GALYEAN, MICHAEL - Texas Tech University; BALLOU, MICHAEL - Texas Tech University; MACHADO, VINICIUS - Texas Tech University; Broadway, Paul

Submitted to: Ruminant Physiology International Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/16/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: We evaluated the association of diet type, ruminal acidosis bout frequency, and intraruminal bacterial inoculum concentration upon liver abscess (LA) development in cattle. Beef x dairy steers (n = 40, initial BW = 236 ± 24 lb) were assigned randomly to 1 of 5 treatments that included either a high-dose (HD; 1^109 and 1^109 CFU/mL) or a low-dose (LD; 1x10^6 and 1x10^6 CFU/mL) of Fusobacterium necrophorum subsp. necrophorum and Salmonella enterica, respectively. Treatments included: NCON = high-forage diet with no intraruminal inoculation; CON+HD = high-forage diet with a single, HD inoculation; 2AD+HD = 2 acidotic diet cycles with a single, HD inoculation; 4AD+3LD = 4 acidotic diet cycles with a series of 3 LD inoculations; and 4AD+HD = 4 acidotic diet cycles with a single, HD inoculation. Individual animal was the experimental unit. Continuous data were analyzed using mixed models, and categorical data were analyzed as binomial proportions with treatment, time, and their interactions as the fixed effects. Hematology was evaluated before harvest on d 21 to investigate systemic disease; minimal differences were observed in hematology. Although no difference was observed in ruminal damage among treatments (P = 0.79), steers with LA presented with 8 percentage points greater ruminal damage than steers without LA. Steers consuming only high-forage diet treatments also presented with rumenitis. Prevalence of LA was 0, 37.5, 37.5, 50, and 12.5% for NCON, CON+HD, 2AD+HD, 4AD+3LD, and 4AD+HD, respectively (P = 0.68). A key observation of this study was that steers fed a high-forage diet presented with LA when dosed with of F. necrophorum and S. enterica, even in the absence of the acidotic diet.