Effects of Dried Distillers’ Grain on Fecal Prevalence and Growth of Escherichia coli O157 in Batch Culture Fermentations from Cattle

Abstract

Distillers' grains (DG), a by-product of ethanol production, are fed to cattle. Associations between Escherichia coli O157 prevalence and feeding of DG were investigated in feedlot cattle (n ‫؍‬ 379) given one of three diets: steam-flaked corn (SFC) and 15% corn silage with 0 or 25% dried distillers' grains (DDG) or SFC with 5% corn silage and 25% DDG. Ten fecal samples were collected from each pen weekly for 12 weeks to isolate E. coli O157. Cattle fed 25% DDG with 5 or 15% silage had a higher (P ‫؍‬ 0.01) prevalence of E. coli O157 than cattle fed a diet without DDG. Batch culture ruminal or fecal microbial fermentations were conducted to evaluate the effect of DDG on E. coli O157 growth. The first study utilized microbial inocula from steers fed SFC or dry-rolled corn with 0 or 25% DDG and included their diet as the substrate. Ruminal microbial fermentations from steers fed DDG had higher E. coli O157 contents than ruminal microbial fermentations from steers fed no DDG (P < 0.05) when no substrate was included. Fecal fermentations showed no DDG effect on E. coli O157 growth. In the second study with DDG as a substrate, ruminal fermentations with 0.5 g DDG had higher (P < 0.01) E. coli O157 concentrations at 24 h than ruminal fermentations with 0, 1, or 2 g DDG. In fecal fermentations, 2 g DDG resulted in a higher concentration (P < 0.05) at 24 h than 0, 0.5, or 1 g DDG. The results indicate that there is a positive association between DDG and E. coli O157 in cattle, and the findings should have important ramifications for food safety.Cattle are major reservoirs for Escherichia coli O157, a significant food-borne pathogen (19,24,32). Asymptomatic colonization by E. coli O157 in cattle occurs in the lower gastrointestinal tract, specifically the mucosal surface of the rectum (31), and the organism is shed in feces (2, 6). There are multiple variables that influence the prevalence and shedding of E. coli O157 in ruminants (2, 34, 37). One of these factors is diet (3,5,6,10,14,40), which may suggest that diet influences the physiological environment of the gut and affects the survival and establishment of E. coli O157.Different diet components have been evaluated to identify associations with E. coli O157 shedding. An epidemiologic study revealed a positive association between cattle receiving barley grain in their diet and E. coli O157 prevalence in feedlot cattle (8), which was confirmed by natural prevalence and challenge model studies (3, 5). Several studies have indicated that forage-fed cattle shed E. coli O157 in their feces for a longer duration than grain-fed cattle (21, 40). Increased amounts of starch reaching the hindgut can increase volatile fatty acid production and reduce the pH in the hindgut, altering the environment for growth and survival of the organism (14, 35).The fermentation of cereal grains for ethanol production results in a coproduct called distillers' grains (DG), which can be used as a livestock feed. This coproduct is the "spent" fraction that remains after distillation of ethanol. T...

Inclusion of Dried or Wet Distillers' Grains at Different Levels in Diets of Feedlot Cattle Affects Fecal Shedding of Escherichia coli O157:H7

“…This study also showed that not only overall prevalence but also high-shedder prevalence was dependent on DG inclusion level. Previous studies documenting the relationship between E. coli O157:H7 prevalence and feeding DG differed in the inclusion level (10 to 50%) and form of DG (wet or dried) fed to cattle; further, the magnitude of the reported association has not been consistent (10,11,28). Although both dried and wet DG have been studied, the two have not been directly compared in terms of their impact on E. coli O157:H7 prevalence.…”

“…Distillers' grains for use in cattle diets are available in wet (WDG) or dry (DDG) form. The association between feeding DG and E. coli O157:H7 prevalence has been shown with both forms (10,28), but no study has directly compared the two forms. The levels of DG supplementation in cattle diets generally range from 10 to 50% (dry matter basis) depending on whether the coproduct is used as a protein or energy source.…”

“…Previous work has shown that cattle fed diets containing distillers' grains (DG), an ethanol fermentation coproduct, have a higher prevalence of E. coli O157:H7 than cattle fed diets without DG (10,28). Distillers' grains are a valuable feed commodity for cattle producers, and use of these coproducts has increased with the expansion of the ethanol industry (14,17).…”

Inclusion of Distillers Dried Grain as Partial Replacement of Wheat Flour and Soybean Meal in the Diet of Juvenile Abalone Haliotis discus hannai

“…At the initiation and the termination of the experiment, abalones in each aquarium were collectively weighed using an electric balance following a 24 h starvation period. tional value and low cost, and it is currently mainly being tested for use as a possible energy source in ruminant diet programs (Jacob et al, 2008). However, due to the enhanced availability and potential cost-benefit of DDG, incorporating DDG into aquafeed may present a large economic value.…”

Impacts of dietary forage and crude protein levels on the shedding of Escherichia coli O157:H7 and Listeria in dairy cattle feces

“…Both bacteria have been associated with numerous outbreaks in the United States (Ratnam et al, 1988;Nightingale et al, 2004;CDC, 2014). Cattle are reservoirs of E.coli O157:H7 as they are found in the lower gastrointestinal tract, specifically the mucosal surface of the rectum (Naylor et al, 2003;Gyles, 2007;Hussein, 2007) and also in feces (Callaway et al, 2003;Berg et al, 2004;Jacob et al, 2008aJacob et al, , 2008b. The detection of Listeria monocytogenes was also reported in the feces of ruminants, particularly cattle (Pell, 1997;Pauly et al, 1999).…”