Nutrigenomic evidence of phytogenic cytoprotective functions in the ovary and liver provides mechanistic support for improved laying hen performance

The study assessed the inclusion level effects of a phytogenic blend (PB) on performance and critical molecular biomarkers related to detoxification (Aryl hydrocarbon receptor; AhR) and antioxidant (Nuclear factor-erythroid 2-related factor 2; Nrf2) responses in layers' ovary and liver. Layers (n = 385; 21-week-old; Hy-Line Brown) were allotted to 5 treatments with 7 replicates of 11 hens each, for a 12-week feeding trial. Treatments were: control (CON) without PB or supplementation with PB at 250 (PB250), 750 (PB750), 1000 (PB1000) and 1500 mg/kg diet (PB1500), respectively. Performance was determined weekly for the 12-week experimental period. At the 6^th and 12^th experimental week ovarian and liver samples were collected for gene expression analysis. Increasing PB inclusion level, improved linearly and quadratically overall laying rate, egg mass and FCR, with optimal (<i>P</i> ≤ 0.001) performance notable in the PB750 compared to CON. The nutrigenomic analysis revealed that PB inclusion resulted (<i>P</i> ≤ 0.05) in consistent beneficial modulation of the AhR/Nrf2 pathway-related genes assessed at the 6^th and 12^th experimental week, both in the ovary and the liver of laying hens. In conclusion, PB beneficially modulated the ovarian and hepatic adaptive cytoprotection and supported the laying performance improvements recorded, with PB750 displaying the optimal benefits.