Further studies on oestrogenic activity in strains of subterranean clover (Trifolium subterraneum L.) in South-western Australia

Abstract

The oestrogenic activity of several strains of subterranean clover was measured by the response in uterine weight in ovariectomized ewes. Large differences in oestrogenic activity between strains were found and a tentative ranking of strains is given.

There were between-site and between-year differences in activity within any one variety.

Oestrogenic activity was maintained when the green clover was dried rapidly in a forced-draught dehydrator. When the same clover was made into hay, there was sometimes a diminution in oestrogenic activity. There was no oestrogenic activity in clover that had set seed and matured in the field.

Cobalt either in the rumen or applied as a fertilizer to the pasture did not affect oestrogenic activity.