Evaluating a Proprietary Tannin-Blend Product as an Alternative to Monensin and Tylosin Phosphate in Feedlot Cattle Diets

This study evaluates the effects of a proprietary tannin blend (BX), supplemented with or without sodium monensin (MON), on beef cattle performance, carcass traits, and health. Steers (<i>n</i> = 2986; initial shrunk body weight (SBW) 254 ± 9.2 kg) were allocated into 48 pens (61–62 steers/pen; 12 pens/treatment) fed for 230 d. Treatments included: (1) no feed additives (CTL); (2) BX (7.95 g/animal daily); (3) MON + Tylosin phosphate (TYL; 437.52 mg MON/animal daily + 80 mg TYL/animal daily); or (4) MON + BX (437.52 mg MON/animal daily + 7.95 g BX/animal daily). Data were analyzed in R 4.2.1 using a randomized block design with pen as the experimental unit. Dry matter intake was lower (<i>p</i> < 0.001) in MON + TYL and MON + BX than in CTL. Steers fed MON + BX had greater carcass-adjusted final SBW (<i>p</i> = 0.002), average daily gain (<i>p</i> = 0.002), fat thickness (<i>p</i> = 0.035), and marbling score (<i>p</i> = 0.046) than BX. Feed conversion improved in MON + TYL and MON + BX (<i>p</i> < 0.001). CLT and BX had higher (<i>p</i> < 0.001) liver abscess prevalence compared to MON + BX and MON + TYL. The addition of BX did not improve the parameters measured. Steers fed MON + BX showed reduced liver abscesses and similar feed efficiency compared to MON + TYL.