Bioactive compounds from Silybum marianum L., and Cynara cardunculus scolymus L. improve the well-being of laying hens: preliminary data.

This study was designed to assess the effectiveness of Silybum marianum L., and Cynara scolymus L. association extract (PHYTO-LAYER™) expressed in silibinin (>2.4g/L), and chlorogenic acid (>2.2g/L) content respectively, provided during 8 weeks (wk) to laying hens raised in enriched cages to improving the liver health and egg quality. A total of 792 Lohmann LSL-White hens at 41 wk of age, randomly assigned to 2 replicated groups, control (Cr) and treated (Tr), 396 each were used. The PHYTO-LAYER™ treatment (TRT) was supplied in drinking water at different time points (T) at a dose of 1 mL/L day, as follows: 1st day (d) of the 41st wk (T0), before the TRT administration for 7 d (T1); 14 d of withdrawal period (T2); other 7 d of TRT (T3); other 14 d of withdrawal period (T4); other 7 d of TRT (T5, end of the trial). At T0, T3 and T5, 13 hens per group were sampled for blood analysis, and 60 eggs per group were evaluated for quality parameters. At T5, the same hens were sacrificed for gut and liver weight, gut pH and liver histological evaluations. The body weight (BW) was recorded at different time points, and the mortality daily. One-Way MANOVA followed by Duncan’s post hoc test was applied to assess the effects of the TRT, time (t), and their combination (TRT-t), fixing the statistical significance at P<0.05. Preliminary results showed that the TRT reduced the serum ALT (P<0.005), and improved the red blood cell (P<0.01), hematocrit (P<0.05) and haemoglobin levels (P<0.005), with a lower increase in BW in the Tr hens (Cr, 1.67±0.13 kg-BW; Tr, 1.69±0.14 kg-BW, P<0.05). The egg quality (egg, yolk, albumen weight, and thickness) was improved after the TRT (P<0.001). However, the Haugh Unit was lower in the Tr group, compared to the Cr (P<0.001). Furthermore, some effects by t and TRT-t were evidenced (P<0.05). At T5, the Tr hens showed a high pH in the proximal tenue tract (P<0.05), and lower liver weight (Cr, 44.61±6.97 g; Tr, 39.91±3.62 g, P<0.05). Liver steatosis was significantly less severe to absent in Tr hens compared to Cr (P<0.05). No mortality was recorded in both groups. From these results, the PHYTO-LAYER™ can support the raised-cage laying hens' health at the late production phase, with a positive influence on blood indices and liver health, with an im-provement of the egg quality parameters, also important for commercial purposes.