The estrogenic effect of silage fodder.

The changes in the amounts of estrogens and in the estrogenic effects were compared with the changes occurring in the quality of silage fodders, which were prepared by three different methods (without any additives, by green-solution method, and with molasses) from the 1977 aftermath, composed of 50% of different kinds of grasses and 50% of red clover. The estrogenic isoflavones known (formononetin, biochanin-A, genistein and daidzein) were analysed quantitatively by liquid chromatography, the estrogenic effect by bioassay using female rats aged 21-22 days as test animals the criteria being the uterine weight, the vaginal opening, and the uterine liquid quantity. Other characteristics of the fodders were determined by 21 laboratory determinations or perceptible estimates. The correlations between the characteristics of the fodder showed that, in addition to the plant estrogens, the amount of lactic acid had significant influences on the estrogenic effect. The pH values and the amount of lactic acid had significant effects also on the changes in the amounts of estrogenic isoflavones known. The quantities of isoflavones and the estrogenic effects varied in fodders ensiled by various methods.