The formula for making biodiesel is: 100 parts fat + 10 parts methonal = 100 parts biodiesel + 10 parts glycerol. However, other substances like water and lye can be used to clean up and/or improve the reactions, which in turn can dilute the glycerol extraction. Glycerol has been fed to ruminants, and research indicates it is a precursor to propionate, a volital fatty acids (VFA) used for energy. Research is presently ongoing, but it appears that including 2 to 4 percent glycerol to cattle feedlot diets may enhance performance and feed efficiency. Much more research is needed in this area to determine the correct feeding levels and the feed ingredients glycerol compliments best.
The first step in producing biodiesel is to extract the oil from crops, such as soybeans, sunflowers, canola, and other oilseeds. In commercial operations, this step is accomplished through a combination of expeller and hexane extraction. Once the oil has been extracted, biodiesel is produced through a process referred to as base catalyzed transesterification. This process separates the glycerol backbone from the triglyceride and converts the fatty acids to methyl esters. Glycerol is a by-product that has historically been used in the cosmetics industry, but limited research has evaluated its usefulness as a feedstuff. More research in this area will likely be conducted as supplies of glycerol increase and it becomes more cost-competitive.
Some companies are marketing on-farm biodiesel production units. These small-scale units typically utilize a screw press and do not use a hexane extraction procedure. This method leaves more oil in the meal, which increases its energy content for use in animal feeds.
The residual meals from biodiesel production are useful as protein supplements. Soybean meal is typically used in the swine and poultry industries due to its superior digestibility and amino acid profile. Sunflower meal and canola meal can be successfully used in a wide variety of beef cattle diets, including backgrounding and finishing rations and cow supplements.
As more biodiesel production facilities are constructed, more oilseed meals will be available for animal feed. This could reduce protein supplementation costs for your beef cattle operation.
