Carbonate Buffer Mixture Alleviates Subacute Rumen Acidosis Induced by Long-Term High-Concentrate Feeding in Dairy Goats by Regulating Rumen Microbiota

This study aimed to elucidate the therapeutic mechanisms of carbonate buffer mixture (CBM) in mitigating subacute rumen acidosis (SARA) by examining its effects on rumen pH, systemic inflammation, and rumen microbiota in a dairy goat model. Using a controlled experimental design, SARA was induced through 8-week high-concentrate diet feeding (70% concentrate, 30% forage), followed by 2-day CBM treatment. Comprehensive analyses included rumen pH monitoring, serum inflammatory marker quantification (IL-1β, TNF-α) by ELISA, rumen barrier integrity assessment through tight junction proteins (TJs) ZO-1, Occludin, and Claudin-3 by western blot analysis, and 16S rRNA sequencing of rumen microbiota. The results demonstrated that CBM administration rapidly elevated depressed rumen pH within 6 h post-treatment while concurrently reducing circulating LPS levels. The analysis of rumen 16S rRNA showed that CBM significantly increased the rumen microbial diversity and abundance of SARA dairy goats. Butyric acid generation groups such as <i>Rikenellaceae_RC9_gut_group</i>, <i>NK4A214_group,</i> and <i>Prevotellaceae UCG-001</i> were selectively enriched, and corresponding functional predictions showed that the butyric acid synthesis pathway (PICRUSt2) was enhanced. These findings suggest that CBM has a multidimensional therapeutic effect by simultaneously correcting rumen acidosis, alleviating systemic inflammation, and restoring microbial balance through pH-dependent and pH-independent mechanisms, providing a scientifically validated nutritional strategy for SARA management in intensive ruminant production systems.