Glycerin touted as viable feed source for livestock

Feed Processing Articles >> North America

Glycerin, a byproduct of biodiesel—an alternative energy source gaining popularity in the U.S. — is now being touted as a viable food source for livestock.

University of Illinois at Urbana-Champaign researchers have discovered that swine diets can include up to 15 percent glycerin, achieving similar results as the pure corn and soybean diet typically used by pork producers. At levels greater than 15 percent, the swine grow slower and feed efficiency is lower.

“If the price was low enough, it could lead to a low-cost diet,” said Michael Ellis, an animal sciences professor at the University of Illinois. “The prices vary with market conditions. Sometimes it is cheap enough to replace other ingredients in the diet. The problem has become that corn and soybeans have become expensive so now there’s more incentive on a cost basis to produce a cheaper diet than corn or soybeans.”

The Illinois researchers reported their findings in the current issue of Journal of Animal Sciences.

Especially with the increased used of biodiesels, glycerin may offer pork produces a cheaper alternative food source.

“It is certainly a suggestion that the supply of glycerin would increase as the production of biodiesel increased,” Ellis said.

Biodiesel blends are used to fuel diesel engines and also can be mixed with heating oil and used in furnaces.

They are produced by chemically reacting vegetable oils or animal fats with alcohol. Liquid glycerin is one of the byproducts of this reaction.

Although some hog farmers already include glycerin in their hogs’ diets, many chose to feed their swine corn and soybeans. These have historically been the most readily available and effective food sources in the U.S. Corn provides energy while soybeans provide protein.

However, prices for corn and soybean have doubled in the last four months, according to Mike Haag, a pork producer in Emington, about two hours southwest of Chicago.

“The interesting thing about this is that it now costs more in feed than it did five or six years ago to raise the entire animal,” Haag said.

When pigs are born they typically weigh 3-4 pounds each and can gain about 2 pounds every day until they are sent to market at around six months of age.

This means at current rates it costs about $95 to feed each hog during the six-month span, Haag said. This does not include other costs involved in raising the animal, including utilities, vet visits and salaries for employees hired to perform manual labor.

Hog producers are constantly looking at new food sources for their swine according to market prices, which may very from month to month, Haag said.

Although he continues to feed his pigs a corn and soybean diet, he knows farmers who have turned to glycerin as an alternative food source.

Many considerations must go into using glycerin in its liquid form, however.

Most swine feeders are designed to handle dry products. To store liquid glycerin, producers may have to install tanks with heaters so the glycerin doesn’t freeze in the winter and may have to adjust their feeders for a liquid product, Haag said.

“You need to make sure when you add these all up that it’s cost efficient,” he said.

Other pork producers have turned to unusual sources for animal feed, including day-old breads and stale cookies from Chicago bakeries. These items can be ground up and put as additives in different diets.

“With corn going up like it is now, I see a lot more people using these alternatives,” Haag said.

Although feeding the swine different diets may affect the color of the meat, he continued, glycerin does not affect the livestock themselves, but rather offers an alternative source of food energy.

Haag said the food fed to animals is a determining factor. “We are always conscientious of that and look at what it does down the road,” he said.

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