PSI-30 - A novel direct-fed microbial influences growth performance, health parameters, and carcass characteristics in feedlot finishing steers

Abstract: Non-hormone-treated beef steers (n=1625; 370.6 ± 8.4 kg) were used to determine the impact of a direct-fed microbial (DFM) on growth performance, carcass characteristics, health parameters, and cost of gain in finishing beef cattle. Steers were sorted into 3 optimal marketing groups for each day of enrollment and randomly assigned, within block, to 1 of 2 treatments (12 replicates per treatment). Treatments included: 1) Control (no DFM), 2) BDP (BOVAMINE DEFEND® Plus containing (50mg/hd/d) Lactobacillus animalis, Propionibacterium freudenreichii, Bacillus licheniformis, and Bacillus subtilis). Steers averaged 133 DOF at time of harvest. Both pens within a block were harvested on the same day. Steers were weighed in drafts on a certified scale by pen at closeout. Hot carcass weights and liver scores were collected at the time of slaughter. Data were analyzed as a completely randomized block design and pen was considered the experimental unit. Dry matter intake and final body weight were not different across treatments. Total outs (deads and removed) throughout the experiment were lower (P < 0.01) for BDP steers. Performance tended to be greater as ADG (P < 0.06) and FE (P < 0.01) were better for steers receiving BDP treatment. Hot carcass weight and quality grade were not different across treatments; however, total liver abscesses were found to be lower (P < 0.01) in steers receiving BDP compared to controls. These data suggest that BOVAMINE DEFEND® Plus supplementation improves growth performance during the finishing phase, reduces overall mortality, and increases return on investment of feedlot cattle.