Expansion of the biodiesel industry has increased supplies of crude glycerin available for
livestock feeding. Catalyzed reactions between methanol and triglycerides from vegetable
oils, such as soybean oil, yield biodiesel and a coproduct, crude glycerin. Approximately
10% of the weight of soybean oil used to produce biodiesel becomes glycerin.
Limited work has been conducted to understand metabolism of glycerin in ruminant
livestock. In previous studies at Kansas State University, feeding crude glycerin at 8%
or less of the diet improved cattle performance. Subsequent laboratory experiments
indicated that low levels of glycerin may improve ruminal fermentation. This study was
conducted to determine whether adding low levels of glycerin to feedlot diets could
affect diet digestibility.