Before implementation of the Veterinary Feed Directive in 2017, medically important antimicrobials, like tylosin, were approved for both therapeutic and sub-therapeutic use. Nevertheless, sub-therapeutic practices are now considered injudicious because their use increases antimicrobial resistance risk. Therefore, heightened consumer concerns have increased the interest in antimicrobial alternatives like direct-fed microbials. Two-hundred forty Angus beef steers (mean initial BW = 263 kg ± 18.0 kg) were assigned randomly to one of three dietary treatments
negative control, dietary supplement contained no tylosin (NCON)
positive control, dietary supplement contained tylosin (PCON)
or novel direct-fed microbial fed at 1 g mixture/steer with 1 × 10