Gut detoxification and antioxidant responses in laying hens supplemented with phytogenics

This study evaluated the effects of a phytogenic blend (PB) on the performance and critical genes relevant to the detoxification (i.e. aryl hydrocarbon receptor pathway) and antioxidant responses (i.e. nuclear factor erythroid 2-related factor 2 pathways) in the duodenum and the caeca of laying hens. The PB consisted of selected Mediterranean plants containing olive oil polyphenols, carvacrol and thymol among its main bioactive components. A total of 385, 21-week-old Hy-Line Brown layers were assigned to one of five dietary treatments with seven replicates of 11 hens each for a 12 week feeding experiment. The experimental treatments included a control corn-soybean meal basal diet with no PB (C) or supplemented with PB at 250 (PB250), 750 (PB750), 1000 (PB1000) or 1,500 mg/kg diet (PB1500). During the experimental period, the 0–6 weeks laying rate, egg mass, feed intake and FCR did not differ among the treatment groups. For the period 7–12 weeks, laying rate, egg mass and FCR were significantly increased with PB inclusion compared to birds fed the C diet. In the duodenum and the caeca, increasing dietary PB concentration beneficially affected ( P ≤0.05) the expression of the majority of the AhR and Nrf2 pathway genes studied. Phytogenic inclusion modulated the layer adaptive cytoprotection in the gut and documented further the improved production, with PB750 displaying optimal benefits. In conclusion, PB inclusion beneficially modulated the layer adaptive cytoprotection in the gut which improved performance, with PB750 displaying the optimal benefits.