A Review of Effect of Saponins on Ruminal Fermentation, Health and Performance of Ruminants

SIMPLE SUMMARY: Saponins are active compounds found in plants, with both positive and negative roles in animal nutrition. They are efficient natural rumen modifiers for manipulating ruminal microbial populations, as well as their composition and fermentation. They suppress ruminal ciliate protozoa and may thus enhance microbial protein-synthesis efficiency while abating methane production. The impact of saponins or saponins-containing plants on the ruminal microflora and fermentation depends on the saponin type and level, diet composition, and the microbial community’s composition and adaptation to saponins. Saponins are more effective at enhancing the performance of animals consuming fibrous diets and may be useful to smallholder livestock farmers in developing countries. ABSTRACT: Saponins are steroid, or triterpene glycoside, compounds found in plants and plant products, mainly legumes. However, some plants containing saponins are toxic. Saponins have both positive and negative roles in animal nutrition. Saponins have been shown to act as membrane-permeabilizing, immunostimulant, hypocholesterolaemic, and defaunating agents in the rumen for the manipulation of ruminal fermentation. Moreover, it has been reported that saponins have impair protein digestion in the gut to interact with cholesterol in the cell membrane, cause cell rupture and selective ruminal protozoa elimination, thus improving N-use efficiency and resulting in a probable increase in ruminant animal performance.