337 Effects of Dietary Supplementation of Saccharomyces Cerevisiae-Based Microbial Additive Containing Fermentation Products on Health, and Performance of Weaned Beef Steers During a 35-d Receiving Period

Abstract We examined the effects of dietary supplementation Saccharomyces cerevisiae-based microbial additive containing fermentation products multiple micro-organisms on health and performance newly weaned beef steers during a 35-d receiving period. Crossbred (n = 80; 12-hour post-weaning; 206 ± 12 kg BW) were stratified by BW into 4 pens (20 per pen) such that each pen had similar at beginning experiment. The assigned to receive corn silage-based diet with no (CON; 2 pens) or supplemented blend live S. cerevisiae cerevisiae, Enterococcus lactis, Bacillus licheniformis, B. subtilis an average 28 g/steer/d for first 21 d (SYNB; pens). Percentage treated bovine respiratory disease (BRD) was calculated treatment. Daily DMI weekly body weights measured. Blood samples collected analyzed mRNA expression 84 immune-related genes plasma metabolome. Compared CON, supplemental SYNB increased (P ≤ 0.05) daily gain (ADG) 7 d. During d, there treatment effect > final BW, DMI, ADG. Over entire period, fed greater 0.01) ADG reduced percentage (35 vs. 50%) animals BRD. Whole blood pro-inflammatory downregulated while anti-inflammatory upregulated in SYNB. Six nutrient metabolic pathways great benefits enriched (FDR This study demonstrated arrival BRD morbidity, improved performance, immune, status over