Synergistic and Individual Effects of Licorice Root and Plantain Herb Extracts Supplemented Through Drinking Water on Performance and Egg Quality in Laying Hens

This study examined the effects of licorice root (Glycyrrhiza glabra) and plantain herb (Plantago major) extracts, individually or combined, in drinking water on laying performance and egg quality in laying hens. A total of 280 Lohmann Brown hens (30 weeks old) were assigned to four groups: (1) control (no extract), (2) licorice root extract (3 ml/l), (3) plantain herb extract (3 ml/l), and (4) licorice root + plantain herb extract (1.5 + 1.5 ml/l). Licorice root extract supplementation resulted in a significantly higher egg weight compared to the control group (P < 0.05). Egg production was also improved in both the licorice root and plantain herb groups relative to the other treatments. Similarly, egg mass and feed efficiency were significantly better in hens receiving licorice root and plantain herb extracts compared to the control (P < 0.05). Regarding egg quality, licorice root extract improved the Haugh unit, while plantain herb extracts enhanced shell quality, both separately and in combination. Overall, licorice root extract positively affected the egg production and quality, whereas plantain herb extract mainly improved shell strength. These findings suggest that supplementation of licorice root or plantain herb extract into drinking water may enhance the performance and egg quality of laying hens.