New research shows you can feed up to 15 percent glycerol without hurting lactating-cow performance.

If you want to try it, here are some suggestions from Shawn Donkin, professor of ruminant nutrition and physiology at PurdueUniversity.

  • Replace 1 pound of corn grain with 0.86 pounds of glycerol in lactating diets.
  • Account for reduced protein. When you remove corn from the diet, you also reduce dietary protein. Compensate for this by feeding high-protein ingredients like corn gluten feed.
  • Provide an adjustment period. Introduce glycerol over a period of seven days to help the rumen adapt to it.
  • Monitor impurities. Crude glycerol may contain impurities, particularly methanol. Adjust the diet based on the level of impurities and their energy content. The methanol content of crude glycerol should not exceed 0.5 percent or 150 parts per million.