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Past research has demonstrated that cattle are a major reservoir for E. coli O157:H7 and that this
pathogen is shed through their feces. Various factors may impact the fecal prevalence of E. coli
O157:H7 in cattle, including their diet. Previous studies have demonstrated that forage-fed cattle
persistently shed E. coli O157:H7 longer than cattle on a primarily corn-based ration. <P>
Cereal grains, such as corn, are rich in starch, which can be digested and fermented to yield
ethanol. The residual product that is present after ethanol distillation is known as wet distillers
grain (WDG). This byproduct is dense in energy and protein and has become a common
component in cattle feedlot rations due to its availability as a byproduct of the ethanol industry.
Significant levels of distillers grains in cattle rations may have the potential to change
gastrointestinal ecology and may alter E. coli O157:H7 prevalence in feces. <P>
Previous research has demonstrated up to a 2.5 fold increase in feedlot pen fecal prevalence for
E. coli O157:H7 when 25 percent dried distillers grain was included in a ration. Other existing
studies however, have shown conflicting results on the effect of wet distillers grains on E. coli
O157:H7 in cattle. <P>
The objective of this research was to determine the effect of the level of wet distiller’s grain in a
feedlot ration(zero versus 40 percent on a dry-matter basis) on the prevalence and level of E. coli
O157:H7 in cattle feces and on cattle hides.
Findings:
In this study, feeding wet distillers grains with solubles in the growing ration was associated with
higher hide and fecal prevalence for E. coli O157:H7 when compared to animals without WDGS.
The WDGS pens of cattle averaged 5.26 ± 2.03 for hide enumeration for E. coli O157:H7. This
result was not statistically different than the results from the control group. However, the percent hide prevalence for E. coli O157:H7 was greater for WDGS fed cattle versus those cattle
receiving the control ration. Overall, the E. coli O157:H7 levels were low for both the
experimental and control groups.
<P> The researchers noted that the percent of positive E. coli O157:H7 positive samples was lowest
during one month of the study (February 2008), which adds support to previous work that
demonstrated seasonality plays a role in pathogen shedding rates. Additionally, the entire spring
was characterized by cooler than normal temperatures, which may have contributed to the lower
levels of E. coli O157:H7 observed during the finishing phase of this study. In general, during
the finishing phase, the animals that received 40 percent WDGS (on a dry matter basis) in their
diet had slightly greater prevalence of E. coli O157:H7 on hides and in feces, however the feces
difference was primarily attributable to one pen.
<P> For complete projects details, view the <a href="http://www.beefresearch.org/CMDocs/BeefResearch/2008_Wells_WDG%20pathog…; target="_blank">Project Summary. </a>