PSI-19 Effect of Increasing Supplementation of Bacillus Spp. on in Vitro Ruminal Fermentation and Nutrient Digestibility

Abstract Probiotics may be an effective alternative to antimicrobials in terms of modifying the ruminal microbial ecology enhance fermentative process and improving animal health production. Although Bacillus spp. have demonstrated a great potential, effects increasing inclusion levels on fermentation profile are unclear. The objective this study was evaluate doses probiotic vitro profile, gas production kinetics, nutrient digestibility, using sorghum silage-based substrate. Incubations were conducted sixteen separate days during 12 24 h. Treatments were: Sorghum-silage only (Control) or silage + one three included at 1, 5 10 times recommended dose (8 × 104 CFU/ml). Ruminal fluid collected from two ruminally cannulated steers fed ad libitum corn diet. Gas pH, true digestibility neutral acid detergent fiber, methane (CH4) concentration volatile fatty acids (VFA) ammonia nitrogen (NH3-N) measured after h incubation. Digestibility starch Inclusion did not affect (P > 0.05) rumen pH. Concentration NH3-N total VFA increased quadratically < with inclusion. decreased molar proportions acetate 0.01) but proportion propionate = 0.02). Total CH4 emissions affected by inclusion, while rate as 0.01). These dose-dependent show promissory results based proportions; however, these should evaluated vivo.