It’s fairly apparent to all that the nation is in the middle of a rush to find alternative fuels, and Iowa is rapidly expanding its ethanol and biodiesel production. Now, a few ISU professors are researching a method to utilize a byproduct of biodiesel: Mix it with animal feed.

“What we’ve found is that crude glycerol, the byproduct of biodiesel, has about the same energy value as corn in feed,” said Peter Lammers, graduate student in animal science and assistant to the researchers.

Until now, crude glycerol was further refined and then used as an ingredient in cosmetic products. But with biodiesel production looking to increase, there will likely be a surplus of the glycerol.

“We’ve had inquiries from pig farmers and biodiesel plants about its economic impact, some risks and benefits, and basic information of the process,” said Mark Honeyman, professor at the ISU research farms and one of the lead researchers.

Honeyman said he thinks there needs to be more research done but so far, it looks very promising.

There was a study to measure the energy rating of glycerol-tested groups of pigs and hens with different levels of glycerol in their diet. The animals had 0, 5, 10 and 20 percent of glycerol in their diets. The results showed the animals adapted well to the new ingredient.

“Glycerol contains about 10 percent more energy than corn does. The problem is that when more than five or ten percent of the diet is glycerol, the mix gets really sticky, so they have trouble practically feeding it,” said Kristjan Bregendahl, assistant professor of animal science. “So it can’t completely replace corn, but it can help.”

The need to find other energy sources besides corn is partly based in economy. Since Iowa uses a lot of corn for production of ethanol aside from what gets eaten, the price of corn was getting too high for most feed manufacturers.

“This stuff is pure energy, and it’s absorbed quickly. It’s like an energy drink for pigs,” said Honeyman.

There are a few drawbacks, however. One of the ingredients used to make biodiesel, methanol, is present in small quantities in the glycerol, and has the possibility of negative side effects on the animals. Brian Kerr, collaborating associate professor of soil tilth, said he thinks the problem is that no biodiesel plant is 100 percent efficient at removing methanol.

“With methanol, at high enough levels, the pig or hen would go blind. So because there’s a small amount of methanol in crude glycerol, it hasn’t been given a rating of GRAS, or Generally Recognized as Safe, by the FDA,” Bregendahl said.

However, if it is affecting animals, the results aren’t apparent.

Kerr said after doing carcass work on the pigs in the study and looking at their feces, they’ve seen no adverse side effects.

“In Europe, there are countries that have approved glycerol with a much higher methanol content than what we have. You almost have to drink methanol straight to really have an issue,” Bregendahl said.

Even with these promising results, it will still be a while before pigs will be getting their energy drink.

“Glycerol is a fairly valuable chemical compound. It can be refined for industrial chemical uses. It’s a pretty lucrative market for biodiesel manufacturers,” Lammers said.

He said the biodiesel manufacturers can then sell it for higher-end uses.

“Everything we’ve done so far is really just examining the energy value, and not to find out what’s practical, and how to use it,” Bregendahl said.

“If we get funding, I’d say we have at least another year of experiments ahead of us.”