Effects of supplementation with Bacillus licheniformis 809 and Bacillus subtilis 810 on colostrum quality, productive performance, nutrient digestibility, and metabolic responses of dairy cows during the transition period

cells/mL) and the percentage of cows with SCC >200,000 cells/mL was reduced (48.2% vs. 75.0%) for BG versus CG. Colostrum quality was also improved in the BG, with higher average Brix values (26.5% vs. 23.9% Brix) and a greater percentage of cows with ≥23% Brix (86.96% vs. 56.52%). No differences were observed in urinary pH, BCS, or most metabolic parameters, except for a trend toward increased leptin and IgA levels in the BG. Fecal scores were improved in the BG during the prepartum period, as was NDF digestibility throughout the entire trial. Lastly, time spent eating (min/d) during before and after calving also tended to be greater for BG cows. Hence, It is concluded that Bacillus spp. supplementation increases DMI, milk production, and fiber digestibility, and colostrum quality. It also reduces milk SCC and negative energy balance and favors immune response, with a trend toward higher serum IgA levels.