effects of licorice (glycyrrhiza glabra) extract on gas production kinetics, degradability, protozoal population, and fermentation parameters in a balanced cattle diet

Medicinal plants are increasingly employed to optimize rumen fermentation and enhance feed efficiency in ruminants. licorice (glycyrrhiza glabra), renowned for its therapeutic applications, particularly in treating gastric ulcers, exhibits antibacterial, antioxidant, antifungal, anticancer, anti-inflammatory, and cytotoxic properties. this study evaluates the impact of licorice extract on rumen fermentation parameters, including gas production kinetics, methane output, protozoal populations, degradability, ph, and volatile fatty acid (vfa) profiles in an in vitro cattle rumen model. licorice extract was incorporated into a balanced cattle diet and assessed using an in vitro rumen fluid system. parameters measured included total gas production, methane output, protozoal counts, dry matter degradability, rumen ph, and vfa composition (acetic, propionic, butyric, valeric, and isovaleric acids). the experimental design compared control and licorice extract-treated samples, with statistical significance determined at p<0.05. licorice extract significantly increased total gas production (178.09 ± 0.44 ml, p<0.05), indicating enhanced microbial fermentation. methane production was significantly reduced (p<0.05). protozoal populations decreased markedly (1,245,000 ± 6,291.53, p<0.05), potentially improving nutrient utilization. dry matter degradability improved significantly (65.30 ± 0.17%, p<0.05). rumen ph remained stable (6.80 ± 0.15, p>0.05). licorice extract significantly altered vfa profiles, increasing valeric, isovaleric, and propionic acid concentrations (p<0.05), while acetic and butyric acid levels remained unchanged (p>0.05). licorice extract enhances rumen fermentation by increasing gas production, reducing methane and protozoal populations, and improving degradability without affecting ph. its selective modulation of vfas underscores its potential to optimize feed efficiency. these findings advocate for licorice extract’s integration into cattle diets to enhance productivity and sustainability. future in vivo studies and dose optimization are recommended to validate these effects and facilitate practical application.