NEBRASKA: Ethanol byproduct used as cattle feed raises e.coli concerns
Posted: January 31st, 2012 - 1:16pm
Source: Journal Star
As the University of Nebraska-Lincoln ramps up a $25 million war against E. coli announced at UNL earlier this week, federal scientists at Clay Center are hot on the trail of one potential source of the troublesome bacteria.
It's wet distillers grain, an increasingly popular item in the state's cattle feedlots.
Peer-reviewed research published in the October Journal of Food Protection shows that feeding high levels of the ethanol production byproduct increases the amount of E. coli 0157:H7 found in cattle manure.
That presents beef producers and processors with the challenge of upgrading sanitation to protect consumers from problems as severe as kidney failure and death.
Research microbiologist Jim Wells headed the team of six at the U.S. Meat Animal Research Center that produced the most recent findings on distillers grain.
A seven-page summary of their results is titled: "Impact of Reducing the Level of Wet Distillers Grains Fed to Cattle Prior to Harvest on Prevalence and Levels of Escherichia coli 0157:H7 in Feces and on Hides."
Wells confirmed last week that feeding cattle a ration containing 40 percent wet distillers grain "did increase prevalence and did increase the number of animals, the percentage of animals in the pen that were shedding."
The scientific conclusions come from a two-year study involving 300 cattle a year. And the findings are similar to those found in a previous two-year study at Clay Center and in related work done at Kansas State University, a partner in UNL's new E. coli initiative.
Wells doesn't expect the link between distillers grain and E. coli to come as a surprise to the meatpacking industry.
"We've been feeding distillers grain now, probably at high levels, for at least five or six years, maybe longer. So I'm sure the industry is aware, because they're monitoring pathogen levels."
Nonetheless, the link between E. coli and distillers grain in this latest study is especially relevant in Nebraska, home of 25 ethanol plants and, typically, in monthly measures, the second-largest number of cattle on feed in the United States.
That means ample supplies of wet distillers grain -- cheaper than corn and offering efficient rates of gain -- are available within 50 or 60 miles of virtually every feedlot in the state.
"It would be fair to say that there's twice as much distillers grain today as there was two years ago, even," said UNL beef feedlot specialist Galen Erickson, "because the supply has increased about twice -- and the incidence of O157 is lower today than it has been in the last 10 years in meat products."
Terry Klopfenstein, a ruminant nutritionist with 46 years' experience at UNL, acknowledged that forces friendly to ethanol gave a cool reception to early research linking distillers grain and E. coli.
At the same time, those regularly critical of ethanol seized on it as one more reason to disparage it.
But Klopfenstein said the ongoing ethanol debate shouldn't get in the way of serious scientific inquiry.
"There may be a bias toward not wanting to have anything wrong with distillers (grain)," he said, "because it works very well in cattle diets. On the other hand, we need to be realistic, and whenever something is not as good as we'd like it to be, we need to know that."
But he and Erickson put several qualifiers on the message that distillers grain-E.coli research is delivering. And Wells, leader of the research team at Clay Center, is careful to do the same.
For example, findings at the U.S. Meat Animal Research Center are based on using 40 percent wet distillers grain measured as dry matter. That's a higher proportion than most cattle feeders use.
Also, the research didn't show a straight-line progression. In other words, there's no evidence that feeding higher and higher levels of distillers grain produced more and more E. coli in manure.
Should the typical cattle feeder cut back on feeding distillers grain as a step toward greater meat safety?
"At this point, there's no indication that would be a good action to take," Wells said.
Klopfenstein said the proximity between ethanol plants and feedlots has given Nebraska "a great competitive advantage."
That advantage is especially pronounced because cattle are close enough to eat a wet product before it goes out of condition. Feedlots farther away don't want to pay the freight for water content and they have to pay extra for drying.
"I was just in a conversation this week about the difference in profit of feeding cattle in Nebraska between, probably, southern Kansas to Texas," he said. "It's a sizable difference."
Mixing distillers grain in moderation into feedlot rations shouldn't be a problem, he said.
"At the levels that I believe it's being fed, on average, in Nebraska -- I don't believe that would affect shedding."