|LONERAGAN, GUY - Texas Tech University|
|HANSON, DEVIN - Texas Tech University|
|Genovese, Kenneth - Ken|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/10/2016
Publication Date: 3/10/2016
Citation: Edrington, T.S., Anderson, R.C., Brown, T.R., Loneragan, G.H., Hanson, D.L., Genovese, K.J., Nisbet, D.J. 2016. Evaluation of sodium chlorate as a pre-harvest intervention for controlling Salmonella in the peripheral lymph nodes of cattle. Meeting Abstract. 1-2.
Technical Abstract: The objective of the current study was to evaluate sodium chlorate as a potential pre-harvest intervention for reducing or eliminating Salmonella from the peripheral lymph nodes of experimentally-infected cattle. The peripheral lymph nodes of Holstein steers (approx. BW = 160 kg; 4 and 6 head in control and chlorate treatments, respectively) were experimentally inoculated with Salmonella Montevideo utilizing an intradermal technique developed in our laboratory. Steers were inoculated every other day for a total of three inoculation events. Sodium chlorate (42 mg/kg BW daily) was provided in the animals' daily grain ration for three successive days initiating on the final day of Salmonella inoculation. Six steers received chlorate and another 4 animals served as controls. Animals were euthanized and necropsied the day following the final chlorate administration and the peripheral lymph nodes (sub-iliac, pre-scapular, and popliteal) removed and cultured quantitatively and qualitatively for Salmonella. Three isolates from each Salmonella positive sample were serogrouped using slide agglutination to confirm they matched the challenge strain (C1). Data were analyzed using SAS software (version 9.2, SAS Institute Inc., Cary, NC). Quantitative (concentrations) and qualitative (prevalence) data were subjected to analysis using the PROC Mixed and PROC Freq procedures, respectively. Salmonella concentrations were lower (P = 0.03) in the popliteal lymph nodes and when all nodes were collectively analyzed in the chlorate treated cattle compared to controls. At a minimum, a numerical decrease in concentration was noted in the nodes of chlorate treated cattle, when examined by individual node (right and left of each type) or when combined by type (popliteal, sub-iliac, and pre-scapular) (Table 1). All lymph nodes were Salmonella positive following qualitative culture and all isolates were confirmed as serogroup C1. Results suggest that chlorate reached the lymph nodes and reduced, albeit slightly, the concentrations of Salmonella within these nodes. Chlorate may have a more profound effect when Salmonella concentrations within these nodes are higher, such as has been reported in cattle at slaughter. Further research is underway to evaluate this potential.