Affiliation: | a United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Centers for Epidemiology and Animal Health, 555 South Howes Street, Suite 200, Fort Collins, CO 80521, USA b College of Veterinary Medicine, University of Illinois, Urbana, IL 61801, USA c United States Department of Agriculture, Agricultural Research Services, National Animal Disease Center, Ames, IA 50010, USA d United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Foreign Animal Disease Diagnostic Laboratory, Plum Island, NY 11944, USA e United States Department of Agriculture, Animal and Plant Health Inspection Service, National Veterinary Services Laboratories, Ames, IA 50010, USA |
Abstract: | In a convenience sample of 100 feedlot operations (included in the United States Department of Agriculture: Animal and Plant Health Inspection Service 1994 Cattle on Feed Evaluation), up to 25 cattle fecal samples were collected and tested for the presence of Salmonella from each of two pens (the pen which contained the most-recent arrivals, and the pen with cattle that had been on feed the longest). One or more Salmonella spp. were recovered from 38 (38.0%) of the 100 feedlots, 52 (26.0%) of the 200 pens and 273 (5.5%) of the 4977 fecal samples collected. Multivariable logistic regression indicated that feeding tallow and feeding whole cottonseed or cottonseed hulls within seven days prior to fecal sample collection was associated with an increased risk of finding Salmonella in a pen. Variables not found to be significantly associated with the detection of Salmonella in a pen included region, operation size, use of sprinklers, time on feed, type of cattle in the pen, number and concentration of cattle in a pen, feeding probiotics, and various other feeds. |