Submitted to: International Association for Food Protection Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2016
Publication Date: 7/31/2016
Citation: Berry, E.D., Wells, J., Arthur, T.M., Schmidt, J.W., Spiehs, M.J., Woodbury, B.L. 2016. Effect of calcium hydroxide application to cattle feedlot pens on Escherichia coli O157:H7 and total E. coli in pen surface manure [Abstract]. Journal of Food Protection. Supp. A(79):P2-122.
Technical Abstract: Introduction: Cattle and beef products are sources of the pathogen Escherichia coli O157:H7. Lime products have a long history of use in cattle production as disinfectants for sick pens, calving pens, and muddy areas, to control the spread of diseases. Lime may also be useful as a preharvest treatment for reducing cattle exposures to and colonization by E. coli O157:H7, thereby reducing risk for beef contamination and human illness. Purpose: The objective was to determine if hydrated lime (Ca(OH)2) can reduce the levels and persistence of E. coli O157:H7 and total E. coli on feedlot pen surfaces. Methods: Cattle were removed from 5 feedlot pens. Four 3 × 6-m plots in each pen were randomly assigned such that one plot of Ca(OH)2 treatment rates of 0, 2.5, 5, and 10% (w/w) was present in each pen. Rakes were used to incorporate Ca(OH)2 into feedlot surface manure (FSM). Five FSM samples were collected from each plot at 0, 1, 7, 14, 21, and 28 d and analyzed separately. Total E. coli concentrations were determined by direct plating, and presence of E. coli O157:H7 was determined by enrichment, immunomagnetic separation, and plating. Results: E. coli O157:H7 prevalence in FSM ranged from 0 to 8% from d 0 to d 7, with no difference by treatment (P > 0.05). E. coli O157:H7 was not detected in any FSM treatment on or after d 14. Concentrations of total E. coli in FSM were 2.07 and 2.65 log CFU/g lower (P < 0.05) immediately after application of 5 and 10% Ca(OH)2 , compared to 0% Ca(OH)2. However, there was no difference in total E. coli concentrations in FSM of any treatment on d 7 or after. Significance: Further work is needed to identify Ca(OH)2 lev