Effects of a gut agility activator on gut parameters in layers
Production performance and gut cytoprotective response in laying hens fed with different phytogenic levels
Authors: Evangelos Anagnostopoulos , Ioannis Brouklogiannis , Vasileios Paraskeuas , Eirini Griela , Andreas Kern , Konstantinos C. Mountzouris
Scientific Abstract: The aim of this work was to evaluate the effects of 5 dietary inclusion levels of a phytogenic feed additive (PFA) on production performance and on underlying inflammatory, detoxification, and antioxidant molecular mechanisms in the duodenum and the ceca of laying hens. The PFA was based on ginger, lemon balm, oregano, and thyme substances. A total of 385 20 wk-old Hy-line Brown layers were randomly assigned into 5 dietary treatments, with 7 replicates of 11 hens each, for a 12-week feeding trial. Experimental treatments received a corn-soybean meal basal diets with no PFA (CON) or supplementation with PFA at 500 (P500), 750 (P750), 1000 (P1000) and 1500 mg/kg diet (P1500), respectively. Layer egg mass, feed intake and feed conversion ratio were determined weekly and reported here on an overall performance basis. Duodenal and cecal intestinal samples from 32-wk-old layers were collected and stored deep frozen, until gene expression analysis with qPCR. Data were analyzed by ANOVA and statistical significance was determined at P<0.05. Linear and quadratic patterns of biological responses to PFA inclusion levels were studied via polynomial contrasts analysis.
Egg mass was significantly increased (P<0.01) with differences up to 4% in the P1000 group, compared to CON. At duodenum, increasing dietary PFA inclusion level down regulated (P<0.05) the expression of most of inflammatory and detoxifying genes involved in nuclear factor-kappa B (NF-kB) and aryl hydrocarbon receptor (AhR) signaling pathways, respectively. On the contrary, most of the antioxidant genes (8 out of 11) implicated in nuclear factor erythroid 2-related factor 2 (Nrf2) pathway were increased (P<0.05) with increasing PFA level, with P1000 being predominately higher than CON. Similarly, at cecal level most of the genes related to NF-kB (12 out of 15) and AhR (3 out of 6) pathway were down regulated (P<0.05), while those involved in the Nrf2 (4 out of 11) pathway were up regulated (P<0.05) with increasing PFA inclusion level with the higher expression levels obtained in treatments P1000 and P1500.
In conclusion, our research data demonstrate that PFA inclusion downregulated layer inflammatory and detoxification gene expression responses, whilst increasing the expression of antioxidant response genes along with an overall layer performance enhancement, with P1000 displaying optimal benefits.
