|Genovese, Kenneth - Ken|
|Jung, Yong Soo|
Submitted to: American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 6/26/2003
Publication Date: N/A
Technical Abstract: Swine can be a reservoir for Salmonella that can be transmitted via pork products. Salmonella can respire anaerobically by reducing nitrate to nitrite via the intracellular enzyme nitrate reductase (NR). However, NR does not differentiate between nitrate and its valence state analog chlorate, which can be converted within the bacterium to cytotoxic chlorite. When added to pure and mixed cultures of bacteria, chlorate killed both E. coli and Salmonella within 24 h. Preliminary in vivo studies indicated that chlorate supplementation reduced E. coli O157:H7, wild-type E. coli and Salmonella in cattle, sheep and swine, respectively. Therefore, an experimental chlorate-containing product (ECP) has been developed for use in food animals. The current study was undertaken to evaluate the effectiveness of ECP during the short-term lairage period immediately prior to harvest. Pig manure (10 kg) was inoculated with 10**3 CFU/g Salmonella Typhimurium and was spread throughout pens housing pigs (n=10) to simulate the introduction of swine to dirty lairage facilities. After 2 h, pigs were given ad libitum feed (controls) or feed supplemented with ECP (ECP) for 4 h. Animals were humanely sacrificed and tonsils, ileocecal lymph nodes, cecal and rectal contents were collected. Fewer pigs treated with ECP had Salmonella-positive tonsils, but not unexpectedly due to the continuous exposure to Salmonella-contaminated feces this difference was not significant (P>0.05). No differences were noted in lymph node or intestinal content Salmonella status, likely due to the very short duration of ECP treatment. However, in a follow-up study using pigs (n=10) naturally colonized with Salmonella, ECP treatment significantly (P < 0.05) reduced natural cecal Salmonella colonization. Thus, these results indicate that ECP could be a viable pre-harvest intervention strategy to reduce Salmonella concentrations in swine, however further research is needed to optimize the effectiveness of ECP during lairage and transport to the slaughter facility.