Effect of Lavandula stoechas and hydrogen peroxide on quails in terms of egg production, liver function, blood parameters, and gene expression

The aim of this study was to evaluate the effects of supplementing Lavandula stoechas oil in the feed and hydrogen peroxide in the water on egg production, hatchability, and slaughter characteristics in quails aged 56–83 days (d) during the egg production period. Simultaneously, the study analyzed the expression levels of the GPx7 and NRF2 genes, blood serum biochemistry, and liver histopathological parameters to assess whether L. stoechas oil supplementation exhibits antioxidant effects in quails treated with hydrogen peroxide. In the study, each group consisted of 15 females and 6 males, with a total of 84 quails used. The study included four groups: a control group with basal feed; a L. stoechas group with 200 mg·kg-1 L. stoechas oil added to the basal feed; hydrogen peroxide group with a basal feed + 5% hydrogen peroxide added to the water; a L. stoechas + hydrogen peroxide group with a basal feed + 200 mg·kg-1 L. stoechas oil + 0.5% hydrogen peroxide added to the water. Each group was replicated three times. In the second 14 d (days 71 to 84), both the control and hydrogen peroxide groups exhibited lower average egg weights (P<0.05) compared to L. stoechas and L. stoechas + hydrogen peroxide groups. Additionally, L. stoechas and L. stoechas + hydrogen peroxide groups showed improved feed conversion efficiency compared to the control group (P<0.05). Furthermore, the fertilization rate and hatching yield were higher in the groups supplemented with L. stoechas oil compared to the control group (P>0.05). Conversely, the group with hydrogen peroxide added to the water exhibited lower yields than the other groups. Furthermore, it was observed that L. stoechas oil increased the GPx7 gene level regardless of gender, thus showing an antioxidant effect, but did not show a significant effect on the NRF2 gene expressionlevel.