Submitted to: Preventive Veterinary Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/1996
Publication Date: N/A
Interpretive Summary: Infection of cattle with Salmonella species results in millions of dollars in lost income to the cattle industry. Additionally, cattle are known carriers of Salmonella which may result in foodborne disease if consumers eat contaminated beef products. The prevalence of Salmonella was determined in the National Animal Health Monitoring Systems Cattle on Feed Evaluation. Additionally, we looked at the management characteristics of the feedlots in order to determine if there were any factors which may increase the likelihood that cattle will become contaminated with Salmonella. Salmonella was isolated from 38% of the feedlots and 5.5% of the fecal specimens were positive. Pens which housed cattle the longest amount of time in the feedlot were also more likely to be positive than pens which held cattle the shortest amount of time. The feeding of tallow and cottonseed product within seven days prior to fecal collection was more elikely to result in the risk of finding Salmonella within a pen and was associated with an increase in the percent of Salmonella positive specimens. Changing the feed and housing practices of cattle in feedlots may decrease the likelihood that cattle will be positive for Salmonella. Ultimately, this means a safer and more wholesome product will be available for the consumer.
Technical Abstract: In a convenience sample of 100 feedlot operations included in the United States 1994 Cattle on Feed Evaluation, up to 25 cattle fecal specimens were collected and tested for the presence of Salmonella from each of 2 pens (the pen which contained the most recent arrivals, and the pen whose cattle were closest to slaughter). One or more Salmonella species were identified dfrom 38 (38.0%) of the 100 feedlots, 52 (26.0%) of the 200 pens, and 273 (5.5%) of the 4,977 fecal samples collected. Multivariate logistic regression indicated the feeding of tallow and the feeding of whole cottonseed or cottonseed hulls within 7 days prior to fecal sample collection to be associated with an increased risk of finding Salmonella in a pen. The mean percent of fecal specimens from which Salmonella was identified was higher for pens occupied by cattle the longest than for pens occupied by cattle the shortest amount of time. In addition, the feeding of tallow and cottonseed products within 7 days prior to fecal collection was associated with an increase in the percent of Salmonella positive specimens, particularly when fed in combination with wheat fines or mids.