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.
abstract: The objective of this study was to determine if wet distillers grains with solubles (WDGS) from corn in diets affected Escherichia coli O157:H7 in growing and finishing cattle; steers (n = 603) were randomly assigned to diets with or without WDGS. Hide and fecal samples were collected monthly (October through June) from each animal for enumeration and enrichment of E. coli O157:H7. In the growing phase (0 or 13.9% WDGS diets), fecal prevalence for E. coli O157:H7 in steers fed a diet with WDGS was twice that of the prevalence in control steers (P < 0.001). In the finishing phase (0 or 40% WDGS diets), the average prevalence in feces (P < 0.001) and on hides (P < 0.001) was higher for cattle fed WDGS. The average percentage of fecal E. coli O157:H7 enumerable samples during the finishing phase for cattle fed WDGS was 2.7% compared with 0.1% for control steers (P < 0.001). The average percentage of E. coli O157:H7 enumerable hide samples was not different between diets, but the cattle fed WDGS had higher levels (P < 0.05) of the pathogen. Animals fed WDGS had higher levels of E. coli (P < 0.001), higher pH values (P < 0.001), and lower concentrations of L-lactate (P < 0.001) in feces than those values of the control steers. These results indicate that feeding 40% WDGS could increase the level and prevalence of E. coli O157:H7 in and on feedlot cattle when E. coli O157:H7 is seasonally low.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Station, U.S. Meat Animal Research Center, Clay Center, Nebraska 68933-0166, USA. jim.wells@ars.usda.gov
authors.forename: J E
authors.initials: JE
authors.lastname: Wells
authors.forename: S D
authors.initials: SD
authors.lastname: Shackelford
authors.forename: E D
authors.initials: ED
authors.lastname: Berry
authors.forename: N
authors.initials: N
authors.lastname: Kalchayanand
authors.forename: M N
authors.initials: MN
authors.lastname: Guerini
authors.forename: V H
authors.initials: VH
authors.lastname: Varel
authors.forename: T M
authors.initials: TM
authors.lastname: Arthur
authors.forename: J M
authors.initials: JM
authors.lastname: Bosilevac
authors.forename: H C
authors.initials: HC
authors.lastname: Freetly
authors.forename: T L
authors.initials: TL
authors.lastname: Wheeler
authors.forename: C L
authors.initials: CL
authors.lastname: Ferrell
authors.forename: M
authors.initials: M
authors.lastname: Koohmaraie
mesh_terms: D000821:Animal Feed / Q000382:microbiology*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000382:microbiology*; D015169:Colony Count, Microbial; D002523:Edible Grain; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D006197:Hair / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D008297:Male; D015995:Prevalence; D011897:Random Allocation; D012621:Seasons; D012995:Solubility; D003313:Zea mays