1. Investigation of Feedlot-level Use of a Direct-fed Microbial on Fecal Shedding of E. coli O157:H7
- Author
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David O. Edache, Joaquin Baruch, Wanda Kreikemeier, Tiruvoor G. Nagaraja, David R. Renter, Dmitriy Smolensky, and Natalia Cernicchiaro
- Subjects
Direct fed microbials ,E. coli O157:H7 ,Fecal prevalence ,Feedlot cattle ,Preharvest ,Food processing and manufacture ,TP368-456 ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Our objectives were to determine whether the feedlot-level use of a direct-fed microbial (DFM; Lactobacillus animalis LA51 and Propionibacterium freudenreichii PF24; Bovamine Defend®, 2 × 109 CFU/g) was associated with fecal prevalence and concentration of E. coli O157:H7, and determine pen- and feedlot-level risk factors associated with fecal E. coli O157:H7 prevalence in cattle pens from commercial feedlot operations. Twenty commercial feedlots in Nebraska, ten that included DFM (DFM) and ten that did not (no-DFM), were sampled during the summer of 2017. In each sampling month, 22 pen-floor fecal samples were collected from three pens in each feedlot. Samples were subjected to cultural and molecular procedures for the detection of E. coli O157:H7 (immunomagnetic separation, plating on selective media, followed by PCR confirmation) and spiral plating for quantification. A total of 1,320 samples from 180 pens of finishing cattle belonging to 20 feedlots, which were sampled three times throughout a 12-week period, were processed and tested. Across all feedlots and sampling months, the mean within-pen prevalence was 13.5% (95% CI = 2.6–47.4%). The association between DFM status and the within-pen prevalence of E. coli O157:H7 depended significantly (p
- Published
- 2024
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