Reports of beef contaminated with pathogenic E. coli 0157 seem to be almost commonplace in recent years. That’s not something I remember from my childhood. So what has changed? A recent study at Kansas State University may hold part of the answer, and, surprisingly, one environmentally useful compound may be implicated.
Veterinary researchers looked at the connection between types of feed and bacterial loads. Cattle fed with distilled grain from ethanol plants had more E. coli 0157 in their digestive systems. In fact, they had about twice the level found in other cattle. The mechanism is not yet understood – researchers suggest that it may be due to digestive changes or increased bacterial nutrition, for example. The details will form the basis for future investigations.
Despite being naturally occurring, these particular bacteria are associated with health problems in humans. Consumption of undercooked meat, unpasteurized dairy products, and produce contaminated with manure are all pathways for human infection. From apple juice to lettuce, carrots to raspberries, hamburgers to raw cheese, there are many ways for people to run afoul of this pathogen.
The connection is not immediately obvious to those outside the industry. Ethanol is produced from grains such as sorghum and corn. It provides an alternative fuel source, particularly as a lower emission motor fuel. Ethanol is often blended with conventional gasoline, decreasing its cost while increasing its octane level. About 46% of US gasoline contains some ethanol, while certain aviation fuels also have some ethanol content. Additionally, ethanol is used in a huge variety of other applications, from toiletries such as hairspray, perfume, soap, and lotion, to pharmaceuticals. Check labels and see: ethanol is in foods such as extracts and beverages; it is used to produce yeast and vinegar. Paints and other chemicals also use ethanol.
After going through drymill processing to yield ethanol, the residual grain is fed to animals – it is considered a high quality feed. Since only the starch portion is used for ethanol production, the remaining parts – protein, minerals, fat, and vitamins – are still available. According to the American Coalition for Ethanol, one bushel of corn (56 pounds) yields nearly three gallons of ethanol and 17 pounds of distillers grain. This grain byproduct can be fed to animals wet or dry, and plants may be located next to feedlots to facilitate this transfer.
Ethanol’s many uses mean there are increasing numbers of plants and plenty of potential feed. From a recycling point of view, it seems to make good economic and environmental sense. One suggested benefit of using distillers grain is reduced pressure on corn growers. However, as shown by this study, unanticipated repercussions may lurk under the surface. Understanding the link between feed and bacterial levels may provide potential solutions. After all, food safety is extremely important, along with sustainable feeding practices, and environmentally conscientious fuels. Until there is more information, this will continue to be a thorny dilemma.
