The benefits of employing saponin-rich plants as feed additives in cattle

Once called anti-nutritional agents, today saponins belong to the favorable phytogenic feed additives (PFA) due to numerous pharmacological activities they exhibit. Saponins are a substantial group of low molecular weight plant secondary metabolites containing either a tetracyclic steroidal or a pentacyclic triterpenoid aglycone with one or more sugar chains. They are widely distributed in higher plants, and to some extent in lower marine animals and bacteria. Two major commercial sources of saponins are Yucca schidigera and Quillaja saponaria. The constantly growing attention paid to saponins as PFA results from their immunostimulatory, anti-inflammatory, hepatoprotective, antibacterial, antiviral and antifungal activity [1]. In recent years, there have been satisfactory in vitro and in vivo data revealing the ability of saponins to inhibit methane production and demonstrating their anti-protozoal activity. Saponins are shown to modify rumen fermentation through direct influence on the composition and activity of rumen protozoa, bacteria, fungi and archaea [2]. Besides, some saponins alter nutrient digestibility by reducing NH₃-N concentration in rumen liquor and increasing the concentration of volatile fatty acids. In addition to the extensive use as methane production modifiers, saponins are considered as potent antiparasitic agents [3].

Although saponins undergo profound degradation in the rumen it is believed that sufficient amount, predominantly in the form of aglycones, gets absorbed and induces systemic effects. Extracts of saponin-rich plants are currently used as dietary additives for livestock and companion animals.

[1] Sprag SG, Light ME, van Staden J. J Ethnopharmacol 2004; 94: 219 – 243

[2] Patra AK, Saxena J. Nutr Res Rev 2009; 22: 204 – 219

[3] Mehlhorn H, Al-Quraishy S, Al-Rasheid KAS, Jatzlau A, Abdel-Ghaffar F. Parasitol Res 2011; 108: 1041 – 1046