Using a novel direct-fed microbial as an alternative for tylosin phosphate to control liver abscesses and decrease antimicrobial use in finishing beef

Authors: HOFFMAN, ASHLEY - Texas Tech University; FERNANDO, SAMODHA - University Of Nebraska; Wells, James - Jim; WOERNER, DALE - Texas Tech University; MANAHAN, JEFFREY - Texas Tech University; LONG, NATHAN - Texas Tech University; MCDANIEL, ZACHARY - Texas Tech University; SMOCK, TAYLOR - Texas Tech University; LINE, DALTON - Texas Tech University; Broadway, Paul; Carroll, Jeffery - Jeff Carroll; Sanchez, Nicole; HALES, KRISTIN - Texas Tech University

Submitted to: Proceeding of Plains Nutrition Council Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2023
Publication Date: 9/1/2023
Citation: Hoffman, A.A., Fernando, S.C., Wells, J., Woerner, D.R., Manahan, J.L., Long, N.S., McDaniel, Z.S., Smock, T.M., Line, D.J., Broadway, P.R., Carroll, J.A., Sanchez, N.C., Hales, K.E. 2023. Using a novel direct-fed microbial as an alternative for tylosin phosphate to control liver abscesses and decrease antimicrobial use in finishing beef. Proceeding of Plains Nutrition Council Symposium. p. 106.

Interpretive Summary:

Technical Abstract: Our objective was to evaluate the use of a novel direct-fed microbial as an alternative to antimicrobials to decrease liver abscesses in feedlot cattle. Angus beef steers (n = 240; initial BW = 580 ± 40.0 lbs) were used in a randomized complete block design comprised of 3 BW blocks and 3 pen replications per treatment. Experimental treatments were randomly assigned to pen within BW block and consisted of: 1) negative control, dietary supplement contained no tylosin phosphate (Tylan-100; Elanco Animal Health, Greenfield, IN; NCON); 2) positive control, dietary supplement contained tylosin phosphate (PCON); 3) positive control with tylosin phosphate removed the last 65 d of the feeding period (PCONW); 4) novel direct-fed microbial fed at 1 g mixture/animal with 1 × 10 exp 11 CFU/g (DFM). By design, initial BW did not differ (P = 0.79) among treatments, and at the end of the 59-d receiving period, there were no differences in final live BW (P = 0.25). From d 0 to d 30, ADG, DMI, DMI as a percentage of BW, and G:F did not differ (P = 0.21). Likewise, the ADG, DMI, DMI as a percentage of BW, and G:F, from d 31 to d 59, did not differ (P = 0.30). In the overall receiving period from d 0 to d 59, there were no differences in ADG, DMI, DMI as a percentage of BW, or G:F (P = 0.20). During the finishing period, live- and carcass-adjusted final BW did not differ (P = 0.57) among treatments. For the overall finishing period, there were no differences in ADG, DMI, DMI as a percentage of BW, or G:F (P = 0.17). Carcass-adjusted ADG, DMI as a percentage of BW, and G:F also did not differ (P = 0.16). Across treatments, no differences in HCW were noted (P = 0.84). Dressing percentage, marbling score, longissimus dorsi (LM) area, 12th-rib fat thickness, and calculated yield grade (YG) were not different among dietary treatments (P = 0.32). Liver abscess incidence and severity were not affected by dietary treatments (P = 0.13). The inclusion of a novel direct-fed microbial in finishing cattle diets did not affect growth performance, carcass characteristics, or the percentage of liver abscesses. The removal of tylosin phosphate 65 d prior to harvest numerically resulted in the lowest frequency of severe liver abscesses when compared to steers not fed tylosin phosphate, but the sample size of abscessed livers is small, so these data should be interpreted with caution.