Location: Livestock Issues ResearchTitle: A probiotic is ineffective in reducing Salmonela shedding in orally-inoculated weaned pigs Author
|Carroll, Jeffery - Jeff Carroll|
|Gart, Elena - Texas A&M University|
|Bryan, Laura - Texas A&M University|
|Lawhon, Sara - Texas A&M University|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 1/8/2016
Publication Date: 2/1/2016
Citation: Broadway, P.R., Carroll, J.A., Sanchez, N.C., Gart, E.V., Bryan, L.K., Lawhon, S.D. 2016. A probiotic is ineffective in reducing Salmonela shedding in orally-inoculated weaned pigs. Journal of Animal Science Supplement. 934 (Supplement 1): 36, Abstract#72.
Technical Abstract: Salmonella shedding proximal to harvest is a significant issue for the swine and meat industries. Probiotic supplementation prior to transport, lairage, and harvest has been suggested as a possible intervention to reduce Salmonella carcass contamination. In this study, a bolus dose of probiotic prior to Salmonella infection was examined as a possible intervention strategy. Weaned pigs (n = 40; 6.1 +/- 2 kg) were individually housed in an environmentally-controlled facility and separated into two treatments 1) fed no probiotic (CON) or 2) fed the CON diet + 20 g of a lactobacillus-based probiotic supplement (PRO) on d -9, -8, -3, -2 relative to oral inoculation on d 0 with 4.7 x 10^9 colony forming units of Salmonella Typhimurium . All animals were confirmed by fecal culture to be negative for Salmonella prior to challenge. Fecal samples were collected daily from days -1 to 3 relative to the challenge. At 72 hours post-inoculation, the pigs were humanely euthanized and tissues were collected to determine the presence and quantity of the inoculated Salmonella. Tissues collected included: mesenteric lymph node (LN), subiliac LN, cecum, liver, spleen, kidney, and gallbladder. There were no treatment differences (P>0.05) in fecal shedding quantities of Salmonella for 3 days post-challenge. There was also no difference between treatments in the concentration of Salmonella in the mesenteric LN (P=0.32). There was a tendency for increased Salmonella concentrations in PRO cecum in comparison to CON (P=0.08; 4.4 vs. 5.2 log colony forming units/gram, respectively) and liver tissue (P=0.06; 0.37 vs. 1.09 log colony forming units/gram, respectively). Increased concentrations of Salmonella were isolated from PRO pigs in the spleen compared to CON (P=0.02; 0.48 vs. 1.56 log colony forming units/gram, respectively) and gallbladder (P=0.01; 0.21 vs. 1.13 log colony forming units/gram, respectively). Interestingly, more Salmonella was isolated from PRO subiliac LN when compared to CON pigs (P=0.036; 0.47 vs 1.57 log colony forming units/gram, respectively). While there was no difference in fecal shedding between treatments, PRO pigs harbored more Salmonella in their internal organs, and more translocation into musculoskeletal lymph occurred in the PRO pigs. Overall, this suggests that the timing and dose of this probiotic was not only ineffective, but was detrimental to the pigs under a Salmonella challenge. Research should be conducted to determine a more optimal supplementation strategy to mitigate the effects of a live pathogen challenge.