Toxicokinetics, Biotransformation, Excretion, and Tissue Residue of Zearalenone-14-Glucoside in Male Sheep

Zearalenone-14-glucoside (Z14G) is a common modified mycotoxin attracting considerable attention due to its high occurrence in feed and food, and its potential to transform into the parent form zearalenone (ZEN) in vivo. However, the toxicokinetic data in ruminants remain scarce. In this study, male sheep (n = 5) were orally administered a single dose of Z14G at 2 mg·kg−1 BW. Serum, rumen fluid, urine, and fecal samples were collected at designated time points, and tissue samples were obtained at slaughter 168 h post-dosing. Concentrations of Z14G, ZEN, α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL), zearalanone (ZAN), and zearalenone-14-sulfate (Z14S) in these samples were determined using liquid chromatography coupled with tandem quadrupole linear ion trap mass spectrometry (LC-Qtrap-MS/MS), so as to explore the absorption, distribution, biotransformation, excretion patterns, and tissue residue profiles of Z14G. The results showed that Z14G was rapidly hydrolyzed in the rumen, with multiple metabolites detected within 1 h. Among these, β-ZOL exhibited concentrations of 154.75 ± 55.66 ng·mL−1, followed by ZEN 83.56 ± 33.36 ng·mL−1. In serum, ZEN, β-ZOL, and Z14G all reached peak concentrations at 30 min, with values of 20.25 ± 2.55, 3.01 ± 0.59 and 2.15 ± 0.78 ng·mL−1, respectively. The half-lives of all three analytes were less than 3 h, with Z14G eliminated the fastest (t1/2 = 0.94 ± 0.31 h) and ZEN the slowest (t1/2 = 2.91 ± 1.49 h). The total excretion of Z14G and its metabolites in feces and urine accounted for 0.90 ± 0.14% and 0.04 ± 0.01%, respectively. Z14G was not detected in any tissues, but ZEN was detected (1.38–3.61 ng·g−1). As the first systematic toxicokinetic investigation of Z14G in ruminants, this study provides critical data for food safety risk assessment of Z14G, and offers a theoretical basis for controlling Z14G contamination in ruminant feed.