Phytogenic Effects on Layer Production Performance and Cytoprotective Response in the Duodenum

SIMPLE SUMMARY: Stressor challenges can lead to oxidative stress that can negatively impact poultry health and production. Phytogenics may exert beneficial effects on performance and product quality and enhance the endogenous antioxidant system. Therefore, the aim of this study was to evaluate the effects of dietary inclusion levels of a phytogenic premix on the production performance and critical detoxification and antioxidant molecular responses in the duodenum of laying hens. The overall laying rate and egg mass were significantly increased by phytogenic premix inclusion compared with the non-supplemented control. Phytogenic inclusion beneficially affected the expression of critical genes related to detoxification and antioxidant capacity. In conclusion, using an analytical nutrigenomics approach, this study provides new knowledge that further supports the noted phytogenic benefits for layer production performance. This knowledge could provide a new basis for diet formulation strategies using phytogenics in commercial conditions with multiple stressor challenges. ABSTRACT: The aim of this study was to evaluate the effects of a phytogenic premix (PP) on the production performance and critical genes relevant to the detoxification (i.e., aryl hydrocarbon receptor pathway) and antioxidant (i.e., nuclear factor erythroid 2-related factor 2 pathway) response in the duodenum of laying hens. The PP was based on bioactive substances derived from ginger, lemon balm, oregano, and thyme (Anco FIT-Poultry). A total of 385 20 week old Hy-Line Brown layers were assigned to five dietary treatments with seven replicates of 11 hens each for a 12-week feeding trial. The experimental treatments included a corn–soybean meal basal diet with no PP (CON) or supplemented with PP at 500 (P500), 750 (P750), 1000 (P1000), and 1500 mg/kg diet (P1500). The overall (1–12 weeks) laying rate (p < 0.001) and egg mass (p = 0.008) were significantly increased in the P1000 group compared with the CON. At the duodenum, increasing dietary PP inclusion levels beneficially affected (p ≤ 0.05) the expression of the majority of the AhR and Nrf2 pathway genes studied. In conclusion, according to the gene expression analysis, PP inclusion resulted in a reduced requirement for detoxification and an increased antioxidant capacity, with most of the effects seen at the PP inclusion range of 750 to 1000 mg/kg diet.