Which cultivars are high in oestrogens?
Meat & Livestock Australia April 1, 2022
Identification of oestrogenic sub-clovers is possible with practice, however with more than 80 registered cultivars and additional field crosses this can be difficult. Resources are available or seek advice from a consultant.
Dwalganup, Geraldton, Dinninup and Yarloop are most likely to contribute high levels of oestrogens in pastures. Tallarook is present only in districts with very high rainfall. Some locally evolved sub clover variants are also highly oestrogenic, including Eden Valley in SA and Book Book in NSW.
Dwalganup
Leaf – crescent with white arms, leaf often has fold, brown flush in winter. Hairy runner. Early flowering.
Geraldton
Leaf – narrow, triangular, distinctly spaced leaflets, band leaf mark and often brown flush midrib. Hairy runner. Early flowering.
Dinninup
Leaf – full crescent with distinctive flush pattern and thin line surrounding leaf mark. Hairy runner. Late flowering.
Yarloop
Leaf – no crescent only white arms, brown flush midrib. Hairless runner. Late flowering. Adapted to waterlogging. Cream/amber seed.
Tallarook
Leaf – crescent with white arms which fade in spring, often brown flush below the leaf mark in winter. Hairy runner. Very late flowering.
The level of oestrogens can be confirmed by testing sub-clover samples, or a veterinarian can conduct a post-mortem to check for signs of clover disease. Regardless, the percentage of oestrogenic sub-clover in the pasture needs to be confirmed to inform paddock management decisions.