title: Potential to reduce Escherichia coli shedding in cattle feces by using sainfoin (Onobrychis viciifolia) forage, tested in vitro and in vivo.
abstract: There is a growing concern about the presence of pathogens in cattle manure and its implications on human and environmental health. The phytochemical-rich forage sainfoin (Onobrychis viciifolia) and purified phenolics (trans-cinnamic acid, p-coumaric acid, and ferulic acid) were evaluated for their ability to reduce the viability of pathogenic Escherichia coli strains, including E. coli O157:H7. MICs were determined using purified phenolics and acetone extracts of sainfoin and alfalfa (Medicago sativa), a non-tannin-containing legume. Ground sainfoin or pure phenolics were mixed with fresh cattle feces and inoculated with a ciprofloxacin-resistant strain of E. coli, O157:H7, to assess its viability at -20 degrees C, 5 degrees C, or 37 degrees C over 14 days. Forty steers were fed either a sainfoin (hay or silage) or alfalfa (hay or silage) diet over a 9-week period. In the in vitro study, the MICs for coumaric (1.2 mg/ml) and cinnamic (1.4 mg/ml) acids were 10- to 20-fold lower than the MICs for sainfoin and alfalfa extracts. In the inoculated feces, the -20 degrees C treatment had death rates which were at least twice as high as those of the 5 degrees C treatment, irrespective of the additive used. Sainfoin was less effective than coumaric acid in reducing E. coli O157:H7 Cip(r) in the inoculated feces. During the animal trial, fecal E. coli numbers declined marginally in the presence of sainfoin (silage and hay) and alfalfa silage but not in the presence of hay, indicating the presence of other phenolics in alfalfa. In conclusion, phenolic-containing forages can be used as a means of minimally reducing E. coli shedding in cattle without affecting animal production.
authors.affiliation: Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Berard
authors.forename: Richard A
authors.initials: RA
authors.lastname: Holley
authors.forename: Tim A
authors.initials: TA
authors.lastname: McAllister
authors.forename: Kim H
authors.initials: KH
authors.lastname: Ominski
authors.forename: Karin M
authors.initials: KM
authors.lastname: Wittenberg
authors.forename: Kristen S
authors.initials: KS
authors.lastname: Bouchard
authors.forename: Jenelle J
authors.initials: JJ
authors.lastname: Bouchard
authors.forename: Denis O
authors.initials: DO
authors.lastname: Krause
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology; D002417:Cattle; D015169:Colony Count, Microbial; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D004927:Escherichia coli Infections / Q000188:drug therapy*; D019453:Escherichia coli O157 / Q000187:drug effects*; D007887:Fabaceae / Q000737:chemistry*; D005243:Feces / Q000382:microbiology*; D005248:Feeding Methods; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D010636:Phenols