Researchers find distillers' grain in cattle feed may contribute to E. coli infection
A new study suggests that the addition of dried distillers' grain, an ethanol by-product, to cattle feed may contribute to the prevalence of E. coli O157 infection in cattle. The researchers from Kansas State University, Manhattan report their findings in the January 2008 issue of the journal Applied and Environmental Microbiology. This is an example of how an emerging industry that opens an entirely new energy paradigm, faces not only opportunities, but many challenges as well.
Escherichia coli O157 is a significant food-borne pathogen of which cattle are major reservoirs. Colonization by E. coli O157 in cattle occurs in the gut and is shed in the feces. Diet is considered to be one of the factors influencing the prevalence and shedding of E. coli O157, emphasizing the need to examine dietary components and their impact on the physiological environment of the gut and the survival of E. coli O157.
Distillers' grain is the coproduct that remains following the distillation of ethanol. It may be dehydrated to produce dried distillers' grain (DDG) which is then commonly used as livestock feed. In the study cattle were administered one of three diets including: no dried distillers' grain, steam-flaked corn and 15% corn silage with 0 to 25% dried distillers' grains, or steam-flaked corn with 5% corn silage and 25% dried distillers' grains, after which fecal samples were collected and tested for E. coli O157. Results showed that cattle fed with 25% dried distillers' grains and 5% or 15% silage had higher prevalence of E. coli O157 than cattle fed a diet without dried distillers' grains:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: ethanol :: dried distillers grains :: corn :: feed :: cattle :: pathogen ::
The results indicate that there is a positive association between dried distillers' grain and E. coli O157 in cattle, and the findings should have important ramifications for food safety, say the researchers.
In the US Midwest alone, ethanol producers generate 10 million tons of DDGs annually. Farmers buy the residue for between US$85 and US$110 per ton and feed it to livestock.
However, many other uses for the by-product have meanwhile been found. DDGs have been found to make an excellent mulch with herbicidal properties, boosting crop yields (previous post). The product's oil fraction is being used commercial as a biodiesel feedstock (more here).
And scientists have found it could make a good solid biofuel for co-firing with coal, or a feedstock for biogas production. Others take the research a step further and see DDGs suitable for making green chemicals like polyhydroxyalkanoate (PHA) used for the production of biodegradable plastics (earlier post).
Image: Tons of distiller’s dried grains being held in storage at a Midwest ethanol plant. Credit: USDA ARS.
References:
M.E. Jacob, J.T. Fox, J.S. Drouillard, D.G. Renter, T.G. Nagaraja, "Effects of dried distillers' grain on fecal prevalence and growth of Escherichia coli O157 in batch culture fermentations from cattle", Applied and Environmental Microbiology, 74. 1: 38-43, 2008, doi:10.1128/AEM.01842-07.
Biopact: Ethanol byproduct boosts crop yields, acts as herbicide - May 07, 2007.
Biopact: GS CleanTech to produce biodiesel from corn ethanol co-product - October 23, 2007
Biopact: Schmack Biogas to build biogas plant coupled to ethanol facility, fed by residues - September 24, 2007
Biopact: Steps to biorefining: new products from biofuel leftovers - August 10, 2007
Escherichia coli O157 is a significant food-borne pathogen of which cattle are major reservoirs. Colonization by E. coli O157 in cattle occurs in the gut and is shed in the feces. Diet is considered to be one of the factors influencing the prevalence and shedding of E. coli O157, emphasizing the need to examine dietary components and their impact on the physiological environment of the gut and the survival of E. coli O157.
Distillers' grain is the coproduct that remains following the distillation of ethanol. It may be dehydrated to produce dried distillers' grain (DDG) which is then commonly used as livestock feed. In the study cattle were administered one of three diets including: no dried distillers' grain, steam-flaked corn and 15% corn silage with 0 to 25% dried distillers' grains, or steam-flaked corn with 5% corn silage and 25% dried distillers' grains, after which fecal samples were collected and tested for E. coli O157. Results showed that cattle fed with 25% dried distillers' grains and 5% or 15% silage had higher prevalence of E. coli O157 than cattle fed a diet without dried distillers' grains:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: ethanol :: dried distillers grains :: corn :: feed :: cattle :: pathogen ::
The results indicate that there is a positive association between dried distillers' grain and E. coli O157 in cattle, and the findings should have important ramifications for food safety, say the researchers.
In the US Midwest alone, ethanol producers generate 10 million tons of DDGs annually. Farmers buy the residue for between US$85 and US$110 per ton and feed it to livestock.
However, many other uses for the by-product have meanwhile been found. DDGs have been found to make an excellent mulch with herbicidal properties, boosting crop yields (previous post). The product's oil fraction is being used commercial as a biodiesel feedstock (more here).
And scientists have found it could make a good solid biofuel for co-firing with coal, or a feedstock for biogas production. Others take the research a step further and see DDGs suitable for making green chemicals like polyhydroxyalkanoate (PHA) used for the production of biodegradable plastics (earlier post).
Image: Tons of distiller’s dried grains being held in storage at a Midwest ethanol plant. Credit: USDA ARS.
References:
M.E. Jacob, J.T. Fox, J.S. Drouillard, D.G. Renter, T.G. Nagaraja, "Effects of dried distillers' grain on fecal prevalence and growth of Escherichia coli O157 in batch culture fermentations from cattle", Applied and Environmental Microbiology, 74. 1: 38-43, 2008, doi:10.1128/AEM.01842-07.
Biopact: Ethanol byproduct boosts crop yields, acts as herbicide - May 07, 2007.
Biopact: GS CleanTech to produce biodiesel from corn ethanol co-product - October 23, 2007
Biopact: Schmack Biogas to build biogas plant coupled to ethanol facility, fed by residues - September 24, 2007
Biopact: Steps to biorefining: new products from biofuel leftovers - August 10, 2007
1 Comments:
I think it needs to be said that, as far as anyone knows, this has never translated into e coli in meat in any of the hundreds of thousands (millions?) of cattle that have been fed with distillers grains.
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