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Abstract The goal of the current study was to develop a pig model to investigate oxidative stress with a low negative impact on piglet welfare. Four independent trials (A, B, C, and D) were performed using a single intraperitoneal shot of lipopolysaccharide (LPS) as an immune challenge, aiming to assess the minimal LPS dose for piglets of different age to trigger a measurable acute oxidative stress response in healthy animals. In trial A, piglets received an LPS dose of 25 µg/KgBW at 41 days post-weaning (p.w.). In trial B, piglets received 25 µg/KgBW of LPS at 28 days p.w., in trials C And D, piglets were injected with 50 µg/KgBW of LPS at 21 days p.w., respectively. Piglets were randomly allocated either to the T1) Control group with saline solution (Ctrl), or T2) LPS challenge (LPS). The oxidative stress response was measured through the enzymatic activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT), in both plasma and intestinal tissues. Intestinal gene expression of oxidative stress and inflammatory markers was assessed. Discomfort behaviors (panting, prostration, trembling, and vomits) were also recorded. Plasmatic and intestinal oxidative stress response was inconsistent across the four trials even when the dose and pig age were similar, possibly due to individual variability. Relative gene expression differences of anti-inflammatory cytokines (IL10), oxidation precursor (iNOS), and antioxidant markers (GPx4, MnSOD, and CAT) were detected between Ctrl and LPS treatment (P |