April 13, 2007

Glycerin effective as supplement in hog diets
 

Glycerin, a biodiesel by-product, has proven to be effective as a supplement in hog diets, according to researchers from Iowa State University and USDA's Agricultural Research Service (ARS).

To study the effect on growth, 5 and 10 percent glycerin feed was fed to pigs from weaning to market weight. Those put on a glycerin-supplemented diet showed equal growth performance as pigs fed on a conventional corn-soymeal diet.

Although a 20 percent glycerin feed trial was also done, the inclusion level was found to be impractical due to flowing problems in a dry self-feeder. Consequently, Mark Honeyman, animal science professor and coordinator of Iowa State's Research Farms, concluded that the 10 percent inclusion level might be the upper limit.

Meanwhile, carcass data collection and meat quality evaluation results are still pending to assess glycerin's impact on meat quality.

On a cautionary note, toxic methanol is used in the process of producing biodiesel from soybean oil. As such, Honeyman said swine and poultry producers considering the glycerin supplement should cooperate with the biodiesel plant to ensure methanol levels are below the Food and Drug Administration's approved level of 150 parts per million in the glycerol.

With the research showing that glycerin has an energy value similar to corn, and increasing ethanol production driving up global corn prices, Honeyman said the biodiesel by-product is being studied as an alternative to corn in swine feed.