A study by researchers based in Kansas, USA, has found that cattle fed on distillers’ grains, a byproduct of ethanol production, have higher concentrations of E. coli O:157 (the one that makes humans ill) in their gut. The researchers said this does not mean livestock producers should stop feeding their animals on distiller’s grain, because more studies are needed to find out why this happens and whether it can be prevented.
The study is the work of Dr TG Nagaraja, professor of diagnostic medicine and pathobiology at Kansas-State (K-State) University College of Veterinary Medicine, and colleagues Jim Drouillard, K-State professor of animal sciences, and Megan Jacob, a K-State doctoral student in pathobiology. There is no information from the University on a journal publication.
Livestock producers feed their cattle on distiller’s grains, giving ethanol producers an added source of income, said the researchers. Unfortunately this appears to increase the prevalence of E. coli O:157 in the hindgut of the cattle affected.
It is normal for this strain of E. coli to be present in healthy cattle, but it is a risk to human health, and people can become infected with the bacteria through eating undercooked meat, raw dairy products, or food contaminated with cattle manure.
“Distiller’s grain is a good animal feed,” said Nagaraja, and it is common for feedlots and ethanol plants to be sited next to each other.
However, there is a growing number of ethanol plants, which means more and more cattle are likely to be fed on distiller’s grain, thus increasing the risk to human health through increased prevalence of E. coli O:157.
The researchers studied the carcass quality of cattle fed distiller’s grain and found, after three rounds of testing, they had nearly twice as much E. coli 0157 in their gut as cattle that were not fed the ethanol byproduct.
Nagaraja said this was a very interesting finding that was “likely to have profound implications in food safety”.
K-State has sponsored and carried out research on animal health and food safety to the tune of 70 million US dollars since 1999, and has 150 staff working in the field, both of which, says K-State’s press statement, demonstrates the University’s commitment to the issue.
Over the next few years, K-State will concentrate on discovering why cattle fed distiller’s grain have higher levels of E. coli O:157 in their gut. Nagaraja said it could be either the animals’ gut changes when fed on distillers’ grain, or the grain itself is a beneficial environment for the bacteria.
Nagaraja said they realize they can’t tell livestock producers to stop using distillers’ grain.
“Feeding cattle distiller’s grain is a big economic advantage for ethanol plants,” he explained.
“What we want to do is not only understand the reasons why O:157 increases, but also find a way to prevent that from happening,” added Nagaraja.
One leading meat producing area of the US is the state of Nebraska. According to one of the state’s regional newspapers, the Grand Island Independent, by the end of this year, Nebraska will be using about 800 million bushels of corn to make ethanol. Last year, 7.23 billion pounds of red meat came out of Nebraska’s slaughter houses. Randy Kleinm director of market development for the Corn Board of Nebraska told the Grand Island Independent that:
“Distillers grains have outstanding nutritional properties for cattle and can be mixed into normal rations, combined with lower-cost forages to make a great feed or even simply dumped onto cornstalk stubble for foraging cattle.”
“In each case, cattle performance improves and costs go down,” he added.
Click here for Kansas State University College of Veterinary Medicine.
Written by: Catharine Paddock