Effect of novel probiotics on gut microbiota to alliviate hepatic lipidosis in dairy cattle.

This study evaluated the effects of two novel probiotics on gut microbiota composition, metabolic health, liver function, lipid metabolism, and milk production after calving to evaluate the effects of probiotic supplementation during the early lactation phase over a 60-day period. Thirty cows were randomly assigned to one of three groups: control (no probiotics), Probiotic A (P1; Lactobacillus spp., 1 × 10 CFU/day), or Probiotic B (P2; Bifidobacterium spp., 1 × 10 CFU/day). Fecal, blood, and liver samples were collected at days 0, 15, 30, 45, and 60. Gut microbiota analysis using PCR revealed that from day 15 onwards, P1 and P2 groups exhibited significantly higher abundances of Firmicutes and Bacteroidetes compared to controls (p < 0.05). Metabolic health assessments showed that blood glucose levels were significantly higher (p < 0.05) and non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) levels were significantly lower (p < 0.05) in probiotic-supplemented groups, particularly in P2. Liver function markers (ALT, AST, and hepatic triacylglycerol content) were significantly improved (p < 0.05) in probiotic-fed cows. Histopathology confirmed reduced hepatocyte swelling and lipid accumulation in the probiotic groups. Milk production significantly increased (p < 0.05) in probiotic-supplemented cows, with P2 achieving the highest yields. Data were analyzed using repeated measures ANOVA followed by Tukey's post hoc test (p < 0.05). These results demonstrate that probiotic supplementation, particularly P 1, effectively modulates gut microbiota, improves metabolic and liver health, and enhances productivity in dairy cows.