What is corn gluten feed?

Corn gluten feed is the fiber and steep liquor left when a wet mill separates the starch and gluten out of corn. It comes from wet corn milling, the process that makes cornstarch and sweeteners, not from ethanol, and it is a different feed from corn gluten meal despite the near-identical name. Corn gluten feed is a mid-protein energy feed; corn gluten meal is the concentrated protein fraction at nearly three times the protein.

How it is made

A wet mill steeps corn, then splits it into starch, gluten, germ for oil, and the leftover bran and steep. That leftover, the bran plus the concentrated steep liquor, is corn gluten feed. It is sold wet near the plant or dried and pelleted for shipping. Because the starch and the high-protein gluten are pulled out for other products, what remains is fiber, some residual protein, and the minerals concentrated in the steep.

Protein and energy

On a dry-matter basis corn gluten feed runs roughly 21 to 24 percent crude protein, higher than corn but well below the oilseed meals. Its energy comes from digestible fiber rather than starch, so on high-forage diets its TDN pencils close to corn's, while in a high-grain ration it falls short of corn because there is no starch to ferment. Mississippi State University Extension puts its feeding value near corn's when fed at about half a percent of body weight on forage-based diets.

Who feeds it and the limits

Cattle take most of it, in both beef and dairy rations, where the fiber and the moderate protein fit well. Two constraints matter. It is low in calcium and high in phosphorus, so the mineral has to be balanced, and Mississippi State Extension advises keeping it under about half of dry-matter intake. It can also carry meaningful sulfur, and University of Minnesota Extension warns that high dietary sulfur can cause polioencephalomalacia, a risk worth watching in growing calves on higher inclusions.

Worked example: reading the board

The chart above is the live corn gluten feed board price in dollars per ton. Read the latest point as this week's price, then take it to the leaderboard, which converts it to a cost per pound of protein and energy so you can rank it against corn and soybean meal rather than judge it on the ton price alone. The corn gluten feed versus corn spread tracks the energy comparison over time.

The Ration reports the USDA corn gluten feed price as published, per ton, and does the cost-per-nutrient math on it. It does not tell a reader what to feed or at what rate.