Glycerin as Cattle Feed Being Studied

Monty Kerley, professor of ruminant nutrition in the College of Agriculture, Food, and Natural Resources at the Missouri University-Columbia, is examining the effectiveness of glycerin as cattle feed. Through November, the researcher will monitor the growth habits of 60 calves from various breeds to determine if the by-product of biodiesel production provides a healthy main course to cattle. The study has two main priorities: first, to determine if glycerin has a positive or negative effect on calves’ growth performance; and second, to assess its impact, if any, on meat quality.

The cattle have been separated into groups of three, each consuming differing amounts, from zero to 20 percent, of glycerin during their daily diet. In addition to monitoring feeding limits and growth patterns, Kerley also is analyzing how cattle metabolize the varying amounts of glycerin. Unlike the dry feeds they are accustomed to eating, Kerley said the glycerin is liquid based and comes mostly from the processing of biodiesel using soybean oil. He also said it meets stringent Food and Drug Administration regulations.

“We’re really looking at the energy value and how it compares to corn,” Kerley said. “When the animal consumes glycerin, it’s absorbed and the glycerin is used to make glucose. Actually, it’s like feeding sugar to a cow. Because it’s liquid, there are two things we worry about: one, how much can be used in the diet before it changes the form of the diet; and two, is there a limit to how much glycerin can be processed by the animal? We’ll feed it to them for a period of 160 to 180 days.”

Kerley said developing usages for glycerin necessitates this type of research. In recent years, academic scientists and private-sector companies have been racing to find solutions and applications for the by-product. An alternative food source for cattle is but one possibility; however, it’s likely only a short-term option for the cattle industry.

“We probably have a three- to five-year window to use this for animal feed at a reduced cost,” Kerley said. “This glycerin is a wonderful starting compound for building other compounds that can be applied to numerous industrial purposes. After three to five years, you’ll see industrial applications utilizing this glycerin, and that may price it out of the animal feed industry.” Glycerin is currently less expensive than corn, which is most commonly used as cattle feed.

“Originally, the biodiesel plants were concerned with just getting rid of this material, but data shows that glycerin has energy feed value equal to corn,” Kerley said. “If you can get glycerin for less than corn, that’s obviously a sizeable savings.”

The $50,000 research project is funded by the National Biodiesel Board in close association with the Missouri Soybean Merchandising Council.

August 2007 RENDER | back