In Exp. 2 ruminally fistulated steers were fed 3 treatments in a replicated 3×3 Latin square : (1)0%,(2)8%,and (3)16% glycerin (DM basis). Increasing dietary glycerin decreased (trend;P=0.06)DMI. Glycerin inclusion did not affect mean ruminal pH (P=0.61),24-h in situ DM (P=0.38)or NDF disappearance(P=0.51). There was a glycerin ×time interaction (P=0.05)for acetate concentration. At 3 and 6 h after feeding acetate was reduced with increasing glycerin.Mean propionate concentration(P=0.01)increased. Wheres mean acetate-to-propionate ratio(P