Saponins are generally not a problem in tropical forage legumes. However, they are common in several temperate forage legumes. The use of alfalfa, (Medicago sativa, in supplemental protein meals for swine and poultry is limited by its saponin content. Although alfalfa contains several saponins (medicagenic acid, soyasapogenol A, soyasapogenol B, lucernic acid ), medicagenic acid appears to be the one responsible for its antinutritional effects. Saponin content in alfalfa foliage is low in spring and fall and high in midsummer. Low-saponin cultivars of alfalfa have been developed. The seeds and foliage of chickpeas (Cicer arietinum), soybeans ( ), and common beans ( ) also contain saponins. Several rangeland weeds in the US including corn cockle (Agrostemma githago, soapwort (Saponaria officinalis), cow cockle (Saponaria vaccaria), and broomweed (Gutierrezia sarothrae) cause serious toxicity problems for grazing livestock because of their saponins. Alfombrilla (Drymaria arenaroides) is a weed in northern Mexico containing @3% saponins that is responsible for cattle losses in Mexico and has potential for spread to the southwest U.S. Yucca contains sarsaponins and is occassionally grazed by cattle. However, research indicates that sarsaponins might actually be beneficial to rumen digestion. Other plants containing saponins include Christmas Rose (Helleborus niger), Horse Chestnut trees (Aesculus hippocastanum), Asparagus fern (Asparagus officinalis), and Daisies (Bellis perennis).
http://www.ansci.cornell.edu/plants/toxicagents/saponin.html
Chris
http://www.ansci.cornell.edu/plants/toxicagents/saponin.html
Chris