ARS: biodiesel byproduct effective in pig feed
Researchers at Iowa State University and the US
Department of Agriculture's Agricultural Research Services (ARS) discovered that
a biodiesel by-product in pig feed is effective to pigs.
In a growth study, 5 and 10% glycerin was fed to pigs from weaning to market
weight. Results showed equal growth performance between the
glycerin-supplemented diet and a more conventional corn-soymeal
Brian Kerr, an ARS research leader
and collaborating associate professor of animal science, directed the glycerin
feed trials. In the study, both nursery and finishing pigs were fed at levels of
5, 10 and 20% glycerin. These studies showed the glycerin is readily used by
pigs and has an energy value similar to corn.
One problem identified
in the swine metabolism trial is that the diet containing 20% glycerol would not
have flowed well in a dry self-feeder so Mark Honeyman, animal science professor
and coordinator of Iowa State's Research Farms said the 10% inclusion level may
be the upper limit. Bregendahl described the laying-hen diets that included 10
to 15% crude glycerin as 'rather sticky.'
also are questions about how glycerin might impact meat quality. The swine
project includes carcass data collection and meat quality evaluations, with
those results pending.
Another question centers on the fact that when
biodiesel is produced from soybean oil, methanol is used in the process.
Methanol can be toxic, so Honeyman said swine and poultry producers interested
in trying glycerin as part of a feed ration would need to work with the
biodiesel plant to make sure methanol levels are below the Food and Drug
Administration (FDA) approved level of 150 parts per million in the
With the rapid expansion of
ethanol and biodiesel production in Iowa, there are questions about possible
uses for what remains after these alternative fuels leave the plant. So far, the
use of ethanol by-products in animal feed has received most of the
Biodiesel often is made from soybean or vegetable oil,
with crude glycerin the resulting by-product. This compound, which currently is
used in such things as hand lotions, cosmetics and shampoo, is a pure energy
"With an increase in biodiesel
production comes a surplus of crude glycerin," said Honeyman. "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."
Kerr, Honeyman and Bregendahl, along
with other Iowa State researchers, have a series of funding proposals in the
works to further examine the use of crude glycerin in diets for nursery and
finishing pigs, sows, broilers and layers.
â€¢ Iowa State
â€¢ United States
Department of Agriculture (USDA)
â€¢ Agricultural Research Center (ARS)
â€¢ Food and Drug Administration
For the latest pig news, subscribe here
To comment, login here
Or register to be able to comment.