Intravenous trimethylamine N-oxide infusion does not modify circulating markers of liver health, glucose tolerance, and milk production in early-lactation cows

In rodents and humans, the gut bacteria-derived metabolite trimethylamine N-oxide (TMAO) has been implicated in progression of cardiovascular disease, chronic kidney fatty liver, insulin resistance; however, effects TMAO on dairy cattle health milk production have not defined. We aimed to determine whether intravenous infusion modifies measures liver health, glucose tolerance, early-lactation cows. Eight Holstein cows (30.4 ± 6.41 d milk; 2.88 0.83 lactations) were enrolled a study with replicated 4 × Latin square design. Cows intravenously infused at 0 (control), 20, 40, or 60 g/d for 6 d. Washout periods lasted 9 Intravenous tolerance tests (GTT) occurred 5. Blood was collected daily. Milk −1, 0, 5, 6. Urine −1 Circulating metabolites, components, concentrations milk, urine, plasma quantified. Data analyzed using mixed model that included fixed treatment. Concentrations plasma, urine increased linearly increasing dose. Dry matter intake modified by Daily triacylglycerol, acid (FA), modified. Serum albumin, total protein, globulin, bilirubin, direct aspartate aminotransferase, γ-glutamyl transferase, glutamate dehydrogenase also GTT glucose, FA, Plasma total, reduced, oxidized glutathione conclude 6-d does influence