PSI-28 - Efficacy of a Binder on Aflatoxin B1 and Per- and Poly-fluoroalkyl Substances (PFAS) Levels under In Vitro Ruminal Conditions

Abstract: This study was conducted to evaluate the efficacy of aluminum-pillared montmorillonite clay (CLY) in sequestering aflatoxin B₁ (AF1) and per- and poly-fluoroalkyl substances (PFAS) under in vitro ruminal fluid conditions. For AF1 treatments (only), ground alfalfa (3 g) was weighed into 250 mL bottles and sterilized before adding sterile rumen fluid and McDougall’s buffer (25 and 75 mL, respectively) to mitigate AFB1 degradation. Aflatoxin B₁ from Aspergillus flavus was added to each alfalfa bottle to reach 10 µg/mL of media. For PFOS treatments (only), 3.0 g of ground PFAS-contaminated (naturally) timothy grass was weighed into 250 mL bottles, with non-sterilized rumen media added at the same previously outlined ratio. For each toxin, three bottles received CLY (1.7% w/w of fresh forage), and three others remained untreated (CON). All bottles were incubated for 48 hours at 39°C then centrifuged (8,000 x g) to allow the supernatant collection for toxin analysis. Toxin concentrations were determined using mass spectroscopy. For PFAS only, the bottles were capped with ANKOM RF gas production sensors, while AF1 bottles were closed with regular caps. The PROC NLIN procedure of SAS Studio was used to estimate the asymptotic maximal, rate, and lag of gas production for PFAS bottles. The AF1 and PFAS results were analyzed separately. A complete randomized design was used to analyze the data with PROC GLM of SAS (v9.4). The concentration of AF1 in rumen media for AF1-CLY was 0.407 vs. 1.39 µg/mL in AF1-CON (P=0.01), which resulted in an average binding of 68.3% relative to the control. For PFAS, CLY and CON were not different (P>0.05) for asymptotic maximal, rate, and lag of gas production (mean = 150.4 ± 4.60 ml/g DM, mean = 6.03 ± 0.25 %/h, and mean = 0 ± 0 h, respectively). In conclusion, the inclusion of CLY could be a potential strategy to sequester toxins in ruminants.