Postbiotics stabilize rumen microbiome during SARA Postbiotics from Saccharomyces cerevisiae fermentation stabilize rumen solids microbiota and promote microbial network interactions and diversity of hub taxa during grain-based subacute ruminal acido

Subacute ruminal acidosis (SARA) causes health problems and economic losses in dairy farms. We evaluated the effects of two commercially available postbiotics from Saccharomyces cerevisiae fermentation products SCFP (XPC and NutriTek) in lactating dairy cows during grain-based SARA challenges. We found SARA reduced the richness and evenness of rumen solid microbiota, and its predicted amino acid metabolic pathways. The SARA challenges also reduced the number of hub taxa and their composition in the microbial co-occurrence networks. Supplementation with NutriTek postbiotics attenuated the reduction in the number of hub taxa, the populations of fibrolytic bacteria and nitrogen metabolism of rumen solid microbiota during SARA. Besides, NutriTek at higher dose maintained the network characteristics of the rumen solid microbiota during SARA challenges. These findings may help to develop the reasonable strategies to maintain the health of rumen microbiota and improve animal production during SARA challenges.