A thymol-based blend of botanicals reduces Salmonella induced inflammation by altering key inflammatory signaling intermediates differentially depending on dose and in a manner distinct from in-feed antibiotics

Authors: Johnson, Casey; GIOVAGNONI, GIULIA - Vetagro Spa; PERRY, FAMATTA - University Of Delaware; TUGNOLI, BENEDETTA - Vetagro Spa; Caldwell, Denise; Swaggerty, Christina; He, Louis; GRILLI, ESTER - Vetagro Spa; PIVA, ANDREA - Vetagro Spa; Byrd Ii, James; Arsenault, Ryan

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2025
Publication Date: 8/30/2025
Citation: Johnson, C.N., Giovagnoni, G., Perry, F., Tugnoli, B., Caldwell, D.Y., Swaggerty, C.L., He, L.H., Grilli, E., Piva, A., Byrd II, J.A., Arsenault, R.J. 2025. A thymol-based blend of botanicals reduces Salmonella induced inflammation by altering key inflammatory signaling intermediates differentially depending on dose and in a manner distinct from in-feed antibiotics. Poultry Science. 104(11). Article 105713. https://doi.org/10.1016/j.psj.2025.105713.
DOI: https://doi.org/10.1016/j.psj.2025.105713

Interpretive Summary: Inflammation in response to a pathogen infection in chickens diverts energy away from growth and towards the immune system, this includes potential foodborne pathogens that can make people sick. As production animals, chickens’ growth and health status are of the utmost importance, and for the consumer keeping them free of foodborne pathogens is critical. In this study, we evaluated the impact of two doses of a blend of natural products that are often used as feed additives in industry on growth and health status of broiler chickens challenged with Salmonella. Additionally, we compared the impact of the blend to that of two different in-feed antibiotics in birds challenged with Salmonella. Birds from all groups were evaluated for Salmonella presence in their gut and liver. Weight measurements were taken and growth over time was compared between groups. Results showed that the higher dose of the blend reduced indicators of inflammation and the chickens tested negative for Salmonella by the end of the study. From this study we can conclude that the blend tested at the higher dose can be beneficial to broiler chickens challenged with Salmonella by improving inflammatory state, growth, and health parameters.

Technical Abstract: Inducing inflammation in response to pathogen infection is known to be an energy intensive process. An extended state of inflammation in production animals can be detrimental to performance parameters. Here, we compared two doses of a microencapsulated botanical feed-additive blend and two different antibiotics in the context of a Salmonella Enterica subsp. Enterica serovar Enteritidis (SE) challenge. A total of 500, day-old, straight run chicks (Ross 708) were placed in floor pens (50 chicks/pen) and assigned to 5 groups with 2 replicates each. The groups were all fed with basal diets, without supplementation (control) or supplemented with: tylosin at 25 g/MT (tylosin); neomycin sulfate at 100 g/MT (neomycin); or a botanical blend at inclusions of 500 g/MT (Blend 500) or 1000 g/MT (Blend 1000). All the pens were orally challenged at day 4 with SE at 105 CFU/bird. At 7, 14, 21, and 35-days post hatch, ten animals from each pen were weighed and sacrificed in order to enumerate SE in the ceca and determine SE prevalence in the liver. BAX® System analysis, gene expression, and kinome analysis were performed on jejunum samples collected at day 35. The higher dose of the tested botanical, Blend 1000, showed a statistically significant increase in body weight relative to the other groups, indicating an energy benefit for this group. The Blend 1000 also showed a reduction in protein phosphorylation that corresponds to reduced inflammatory status that was unique compared to Blend 500 and the antibiotics. These birds also showed a clearance of orally inoculated SE showing that reduced inflammation can benefit the broiler chicken in clearance of bacteria while maintaining growth.