The present study was conducted to evaluate the effect of different doses of the Sanguisorba officinalis tannin extract (SOTE) on in vitro methane production, rumen microorganisms and basic rumen fermentation parameters. SOTE contained 451 mg g-1 of total tannins was tested at different doses (0, 1, 4, 10, 20, 40 and 100 mg of SOTE per vessel; the input of tannins was 0, 1.3, 5.1, 12.8, 25.6, 5...
