Structural and quantitative changes of saponins in fresh alfalfa compared to alfalfa silage.

The nutrient content of fresh material and silages remained relatively constant, with some variations in the crude protein content of the selected alfalfa varieties. The total concentration of saponins increased two- to three-fold after ensilation over the levels present in fresh alfalfa material. The increases in saponin concentration showed a negative linear relationship between protein on a dry matter basis and saponin content. These findings are significant because no known published data have shown this transformation in the ensiling of alfalfa. © 2018 Society of Chemical Industry.