PS4-8. In Vitro Antimicrobial Efficacy and Ph Modulation in Different Water Sources of a Monoglyceride, Natural Extract and Organic Acid–based Feed Mitigant Against Salmonella Typhimurium

Feed is recognized as a potential vehicle for delivering pathogens including Salmonella, to livestock. From a One Health perspective, increasing regulatory and consumer pressure exists to identify effective alternatives to the current industry standard formaldehyde-based feed sanitizers in the swine and poultry industries. FeedArmor (FA; Furst McNess Company, Rockford, Illinois) is a monoglyceride, natural extract and organic acid–based feed mitigant with strong antimicrobial properties and pH-modulating capacity, making it a promising candidate to provide an alternative to formaldehyde-based products. This study evaluated the in vitro antimicrobial activity of FA against Salmonella Typhimurium and assessed its pH modulation properties in water sourced from Western Texas (WTX) and Georgia (GA), which differ in baseline pH and hardness. Minimum inhibitory concentrations (MIC) were determined using microdilution methods, and bacterial counts were quantified at sub-MIC concentrations. To assess pH variability, FA (1%) was dissolved in distilled water and water collected from both regions. Additionally, feed pH was measured in diets containing 0.5, 1.0, 2.0, and 3.0 mg/mL FA prepared with each water source. Statistical analyses (one-way ANOVA with Tukey’s post hoc test) were performed using GraphPad Prism. FA exhibited an MIC of 3 mg/mL against Salmonella Typhimurium. At sub-MIC levels, FA at 2 mg/mL and 2.5 mg/mL significantly reduced bacterial counts by 1.11-log and 1.48-log, respectively compared to the control (0 mg/mL FA) (P < 0.05). The pH of 1% FA dissolved in distilled water was 2.35. The pH of 1% FA dissolved in WTX was significantly higher than that observed in GA water (WTX: 3.72 vs. GA: 3.65; P < 0.05). Feed prepared with WTX water maintained a higher pH across all FA inclusion levels (upto 0.3%) compared with feed prepared using GA (WTX: 6.15 vs. GA: 5.69: P < 0.05). However, FA inclusion up to 3 mg/mL did not significantly alter feed pH (P > 0.05). Collectively, these findings demonstrate that FA possesses strong in vitro antimicrobial activity against Salmonella and can modulate solution pH. Nevertheless, antimicrobial efficacy and pH response may vary depending on water quality characteristics including baseline pH and mineral hardness. Further feed-based and in vivo antimicrobial evaluations are warranted to validate FA’s potential as a safer alternative for improving livestock feed biosecurity.