Identification of the oestrogenic isoflavones in fresh and fermented berseem clover (Trifolium alexandrinum)

Abstract

A thin layer chromatography technique was used to identify and semiquantitate the oestrogenic isoflavones in berseem clover (Trifolium alexandrinum). Biochanin A and genistein were the most prominent isoflavones in all the three cuts of fresh berseem clover. Low concentrations of formononetin and daidzein were also detected. The concentrations of the all oestrogenic isoflavones gradually decreased in the successive cuts. Fermentation of all three fresh cuts in silo or in rumen fluid increased the concentrations of these isoflavones. Incubation of the silage materials with rumen fluid had little effect on the concentrations of the isoflavones. The concentrations of the oestrogenic isoflavones in fresh or fermented materials considered were too small to have any adverse effects on growth or reproduction of farm animals.