|Trampel, D - IOWA STATE UNIVERSITY|
|Hurd, H - IOWA STATE UNIVERSITY|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 25, 2006
Publication Date: November 1, 2006
Citation: Rostagno, M.H., Wesley, I.V., Trampel, D.W., Hurd, H.S. 2006. Salmonella prevalence in market-age turkeys on-farm and at slaughter. Poultry Science. 85(10):1838-1842. Interpretive Summary: During slaughter and processing, Salmonella from the gastrointestinal tract of carrier birds can contaminate carcasses as well as the slaughter and processing line. Although efforts have concentrated primarily on controlling contamination along the slaughter and processing line (i.e., post-harvest), a high proportion of carcasses are still found to be contaminated with Salmonella. The extent to which contamination of carcasses happens is determined by the hygiene inside the abattoir, and the degree of carriage in the live birds entering the abattoir. However, we still do not have a clear understanding of Salmonella epidemiology in the pre-harvest turkey production systems, and most of all, little is known about the prevalence of Salmonella in market-age turkeys as well as about the factors that affect it. As a consequence, effective pre-harvest control measures to reduce the occurrence of this pathogen from the turkey supply are still lacking. Therefore, this study was conducted with the objective of determining if the perimarketing practices of feed withdrawal, catching, loading, transportation, and holding at the abattoir affect the prevalence of Salmonella in market-age turkeys. Additionally, the study is aimed to measure the relative sensitivity of different sample types to estimate Salmonella prevalence in turkeys. This study shows that there is no difference between Salmonella prevalence estimates in market-age turkeys on-farm and at slaughter. Moreover, this study demonstrates that cecal contents constitute the sample of choice to determine the Salmonella infection status of turkeys, and that it may be possible to monitor the Salmonella status of turkey production farms based on samples collected at the abattoir.
Technical Abstract: The objective of this study was to compare the prevalence of Salmonella in market-age turkeys on-farm and at slaughter (i.e., before and after feed withdrawal, catching, loading, transportation, and pre-slaughter holding). Thirty birds were randomly selected from each of six commercial turkey flocks scheduled to be loaded and shipped to an abattoir during the evening of the same day. Selected birds were euthanized on the farm and cloacal contents, large intestine, crop, ceca, liver/gall bladder, and spleen were aseptically collected. At the abattoir, thirty birds from the same flock were randomly selected from the slaughter line, and the crop, ceca, liver/gall bladder, and spleen were collected for subsequent culture at the laboratory. All flocks studied were positive for Salmonella at slaughter. No statistical difference (P>0.05) was found between the overall prevalence found on-farm and at slaughter. At both sampling points, the overall prevalence found was 33.3%. Diverging prevalence estimates were obtained based on the different sample types collected on-farm and at slaughter. In both cases, cecal content samples had the highest relative sensitivity (73.3% on-farm, and 68.3% at slaughter). This study demonstrates that the perimarketing practices of feed withdrawal, catching, loading, transportation, and pre-slaughter holding do not significantly alter the prevalence of Salmonella in market-age turkeys. Therefore, our results suggest that it may be possible to monitor the Salmonella status of turkey production farms based on samples collected at the abattoir.