Dietary Perovskia abrotanoides essential oil and vitamin E improve performance, antioxidant status, and intestinal morphology in laying Japanese quails fed oxidized oil.

This study investigated the effects of dietary oxidized oil, Perovskia abrotanoides essential oil (PAEO), and vitamin E (VE) on productive performance, egg quality, antioxidant status, intestinal morphology, and hepatic gene expression in laying Japanese quails. A total of 480 48-day-old quails were randomly assigned to 8 experimental groups (6 replicates of 10 birds each) in a factorial arrangement (2 × 2 × 2). The factors included oxidized sunflower oil (0 and 2%; peroxide value: 144 mEq O₂/kg), PAEO (0 and 200 mg/kg), and VE (0 and 200 mg/kg) during a 7-week trial. Dietary oxidized oil significantly (P < 0.05) impaired egg production and egg mass, increased feed conversion ratio (FCR), reduced eggshell quality, elevated egg yolk malondialdehyde (MDA), and disrupted intestinal morphology. It also induced oxidative stress, as evidenced by altered hematological and biochemical indices, an unfavorable serum lipid profile, and up-regulation of hepatic Nrf2, SOD, GPx, and NF-κB p65 gene expression. Dietary supplementation with PAEO or VE effectively mitigated these adverse effects, restoring production efficiency, egg oxidative stability, and intestinal integrity. Significant two-way and three-way interactions (P < 0.05) were observed for several hematological, biochemical, lipid-related, and antioxidant variables; notably, the combined inclusion of PAEO and VE improved hematological recovery and reduced serum triglycerides and LDL under oxidative challenge. Furthermore, PAEO and VE each down-regulated hepatic antioxidant- and inflammation-related gene expression, consistent with reduced oxidative burden. In conclusion, dietary PAEO, particularly when combined with VE, represents an effective nutritional strategy to protect laying quails against oxidized oil-induced oxidative damage and productivity loss.