A Preliminary Study on the Effects of Low Doses of Purified Zearalenone in Weaned Female Piglets: A Multi-Organ Toxicity Investigation

Zearalenone (ZEA) is an estrogenic Fusarium mycotoxin widely contaminating feed and feedstuffs, and posing significant risks to animal health. This preliminary study aimed to evaluate the toxicological effects of dietary exposure to purified ZEA at doses ranging from below to above the Chinese regulatory limit (0.15 mg/kg) in weaned female piglets. Twenty piglets were randomly assigned to five groups (four piglets per group) receiving 0, 0.075, 0.15, 0.3, or 0.6 mg/kg ZEA for 42 days. Results suggested that ZEA promoted systemic oxidative stress, evidenced by decreased serum total antioxidant capacity (T-AOC) and increased malondialdehyde (MDA) content in liver across all doses, and in jejunal mucosa at ≥ 0.15 mg/kg (p < 0.01). Growth performance declined only at 0.6 mg/kg during days 29–42 (p < 0.01), while hemoglobin (HGB) levels (p < 0.01) and ileal villus height (p < 0.05) were reduced at all doses. ZEA also caused inflammatory dysregulation, as evidenced by decreased interleukin-4 (IL-4) levels in serum, liver, and intestinal tissues across all doses (p < 0.01), and disrupted reproductive hormones even at 0.075 mg/kg, as indicated by suppressed serum luteinizing hormone (LH) levels (p < 0.01), which progressed to histopathological damage in uterine and ovarian tissues at higher doses. These preliminary findings, together with significant correlations between oxidative stress markers and multi-organ parameters, suggest that low doses of purified ZEA may induce systemic oxidative stress and subclinical multi-organ toxicity in weaned female piglets, highlighting the need to incorporate redox status into risk assessment and to explore potential antioxidant-based mitigation strategies. However, given the small sample size, these results should be interpreted with caution and warrant validation in larger samples.