More Uses for Biodiesel By-products

John Davis

While animal feed products from the production of ethanol have caught most of the attention, researchers are looking at finding more uses for the by-products of biodiesel.

According to this article posted on posted on, Iowa State University and the USDA’s Agricultural Research Services are looking at using glycerin in poultry and swine feed:

Mark Honeyman“With an increase in biodiesel production comes a surplus of crude glycerin,” said Mark Honeyman, animal science professor and coordinator of Iowa State’s Research Farms. “And with an increase in ethanol comes higher corn prices. Since corn is fed to pigs primarily for its energy value, we’re studying the possibility of replacing corn with glycerin in swine feed.”

The USDA’s research has shown that the glycerin has a similar food-energy value to corn… and the pigs will readily eat it.

And the news looks good for chickens as well:

Kristjan BregendahlKristjan Bregendahl, assistant professor of poultry nutrition, conducted a metabolism experiment with 48 laying hens. Typical feed rations that included corn, soybean meal, meat and bone meal, and four levels of crude glycerin – 0, 5, 10, or 15 percent – were fed to the hens to determine the energy value of the glycerin.

“We found the energy in crude glycerin was used with high efficiency by the hens,” Bregendahl said. “And we saw no adverse effects on egg production, egg weight, egg mass or feed consumption in this short experiment.”

The article goes on to say that there are issues in getting the glycerin through the dry self-feeders, as well as problems with methanol in the glycerin, but researchers promise more work will be done.

Biodiesel, Research