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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Meat Safety and Quality » Research » Publications at this Location » Publication #235303
Title: Prevalence and Level of Escherichia coli O157:H7 in Feces and On Hides of Feedlot Steers Fed Diets With or Without Wet Distillers Grains With Solubles

Author
item Wells, James
item Shackelford, Steven
item Berry, Elaine
item Kalchayanand, Norasak
item Varel, Vincent
item Arthur, Terrance
item Bosilevac, Joseph
item Freetly, Harvey
item Wheeler, Tommy
item Ferrell, Calvin
item KOOHMARAIE, MOHAMMAD - FORMER ARS EMPLOYEE

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/18/2009
Publication Date: 4/22/2009
Citation: Wells, J., Shackelford, S.D., Berry, E.D., Kalchayanand, N., Varel, V.H., Arthur, T.M., Bosilevac, J.M., Freetly, H.C., Wheeler, T.L., Ferrell, C.L., Koohmaraie, M. 2009. Prevalence and Level of Escherichia coli O157:H7 in Feces and On Hides of Feedlot Steers Fed Diets With or Without Wet Distillers Grains With Solubles [abstract]. Microbial Ecology 57(3):583-584.

Interpretive Summary: No interpretive summary is required.

Technical Abstract: Studies have indicated distillers grains in cattle diets may alter the shedding of Escherichia coli O157:H7 in feces, thereby increasing the E. coli O157:H7 load on the hide and ultimately on the carcass. To determine if wet distillers grains with solubles (WDGS) in the diet affected E. coli O157:H7 in growing and finishing cattle, weaned steers (n = 603) were blocked by genetic lines and weaning weight, and randomly assigned to dietary treatments (with and without WDGS). At approximately 53 days after weaning, steers were sorted into 8 pens (4 pens per treatment) with 75 to 77 steers per pen. Growing diets with 0% or 13.9% WDGS (as %DM) were fed beginning on d 0 and finishing diets with 0% or 40% WDGS were fed beginning on d 78. Hide and fecal samples were collected from each animal for enumeration and enrichment of E. coli O157:H7 from October through June. In the growing phase, the fecal prevalence for E. coli O157:H7 was twice that in animals fed diets with 13.9% WDGS (P < 0.001), but neither the percentage nor the distribution of E. coli O157:H7 enumerable samples in feces was different for the two diets. In the finishing phase, average fecal prevalence for cattle fed 40% WDGS was 14.9% compared to 1.5% for animals fed corn (P < 0.001), and hide prevalence was 32.8 and 9.2% (P < 0.001), respectively. The average percentage of fecal E. coli O157:H7 enumerable samples during the finishing phase for cattle fed 40% WDGS was 2.7% compared to 0.1% for corn (P < 0.001). The average percentage of E. coli O157:H7 enumerable hide samples was not different (1.9 vs 0.0%, P < 0.06), but the distributions of these counts were different (P < 0.05). Animals fed 40% WDGS had higher levels of generic E. coli (P < 0.001), higher pH (P < 0.001), and lower concentrations of L-lactate (P < 0.001) in their feces. Within cattle fed 40% WDGS, fecal shedding of E. coli O157:H7 was not associated with fecal pH. However, fecal shedding of E. coli O157:H7 from the cattle fed 40% WDGS was associated with lower levels of fecal generic E. coli (6.94 vs 7.06 log10 CFU per g, P < 0.05) and higher fecal concentrations of L-lactate (1.87 vs 1.39 mM, P < 0.01). These results indicate that feeding 40% WDGS (DM basis) may increase the level and prevalence of E. coli O157:H7 in feedlot cattle, although the magnitude of the difference in this study may have been affected by low prevalence in the control pens.