The effects of increasing roughage neutral detergent fiber concentration and bulk density of steam-flaked corn on performance, carcass characteristics, and liver abscesses in finishing beef steers fed diets without tylosin...

Authors: MCDANIEL, ZACH - Texas Tech University; GALYEAN, MICHAEL - Texas Tech University; Broadway, Paul; Carroll, Jeffery - Jeff Carroll; Sanchez, Nicole; HANRATTY, ASHLEE - Texas Tech University; DORNBACH, COLTEN - Texas Tech University; LINE, DALTON - Texas Tech University; SMOCK, TAYLOR - Texas Tech University; HOFFMAN, ASHLEY - Texas Tech University; MANAHAN, JEFF - Texas Tech University; HALES, KRISTIN - Texas Tech University

Submitted to: Applied Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2024
Publication Date: 6/1/2024
Citation: McDaniel, Z.S., Galyean, M.L., Broadway, P.R., Carroll, J.A., Sanchez, N.C., Hanratty, A.N., Dornbach, C.W., Line, D.J., Smock, T.M., Hoffman, A.A., Manahan, J.L., Hales, K.E. 2024. The effects of increasing roughage neutral detergent fiber concentration and bulk density of steam-flaked corn on performance, carcass characteristics, and liver abscesses in finishing beef steers fed diets without tylosin phosphate. Applied Animal Science. 40(3):269-278. https://doi.org/10.15232/aas.2023-02484.
DOI: https://doi.org/10.15232/aas.2023-02484

Interpretive Summary: Liver abscesses form when bacteria invade liver tissue. When liver abscesses are present, decreased growth and carcass performance, and increased feeding days can occur. It is estimated this disease complex costs the beef industry $400 million annually. The antibiotic tylosin phosphate is labeled for decreasing liver abscesses in beef cattle. However, it is important to find other strategies to decrease liver abscesses. USDA-ARS scientists and a university partner studied the effect of different feeding strategies on the incidence of liver abscesses in beef cattle. Results from this study suggest that increasing roughage neutral detergent fiber can decrease liver abscesses. Also, increasing the bulk density of steam flaked corn reduced liver abscesses. These data suggest that different feeding strategies can reduce the frequency of liver abscesses in beef cattle. These results will be of interest to scientists studying liver abscesses, and cattle producers.

Technical Abstract: We evaluated the effects of dietary NDF concentration from alfalfa hay and bulk density of steam-flaked corn (SFC) on growth performance, carcass characteristics, and liver abscesses in finishing beef steers. Crossbred beef steers (n = 214; 60 pens; initial BW 417 ± 11.9 kg) were blocked by BW and assigned randomly to treatments and fed an average of 112 d. The treatments were arranged as a 2 × 3 factorial with 10 pens/simple-effect treatment and consisted of three NDF concentrations from alfalfa hay (3, 4.5, or 6%) and 309 g/L (24 lb/bu) or 412 g/L (32 lb/bu) steam-flaked corn (SFC; 33 or 69% starch availability, respectively). Growth performance and carcass data were analyzed with PROC MIXED of SAS with pen as the experimental unit. Quality grades and liver scores were analyzed as binomial proportions using PROC GLIMMIX. Contrast statements were used to separate linear and quadratic effects of increasing roughage NDF. Dry matter intake responded quadratically from d 0 to 35 (P = 0.04) as roughage NDF increased from 3 to 6%, and DMI increased linearly as roughage NDF increased on d 70 to 105 and d 0 to final (P < 0.04). Otherwise, no differences in growth performance were noted (P = 0.28). Marbling score responded quadratically to roughage level and was greater for steers fed 3% than for those fed 4.5 or 6% roughage NDF. Steers fed 309 g/L SFC tended (P = 0.10) to have a larger longissimus muscle area than those fed 412 g/L SFC. The total percentage of abscessed livers at harvest decreased linearly as roughage NDF was increased from 3 to 6% of DM (P < 0.01) as did the presence of A+ abscesses (P = 0.03). In addition, total liver abscesses were 11.7% less (P = 0.05) in steers fed 412 vs. 309 g/L SFC. Results suggest that increasing roughage NDF and bulk density of SFC are dietary strategies that can decrease the presence of liver abscesses at harvest without negatively affecting growth performance.