Red Clover

We're rewarded by Government for reducing chemical inputs to maintain/return pasture to traditional hay meadow. Yes it looks great, stock benefit from the rich mixture and high quality hay is produced for winter feed.

But this week the results of a research study, by the University of Aberystwyth, supported an assertion by farming bodies that the red clover found in our meadows is harmful to breeding ewes if grazed six weeks before and up until six weeks after tupping.

In summary:

• Red clover is a greater risk to sheep fertility than white clover
• Phytoestrogen (see below) levels are higher in Spring and decline after flowering
• Switching ewes between high and low estrogen fields reduced effects on fertility
• Ewes prefer clover to grass, so a even a limited amount will pose a problem
• A higher phytoestrogen level can be found in red clover hay compared with pasture
• Tups suffered no ill effects.

In short the farms ability to produce lambs is at risk if female sheep graze where red clover is present. But what if your farm comprises a majority of pasture with red clover? Tupping is usually scheduled for November, so a pasture plan would need to take into account three months where ewes are kept on fields that have been historically sprayed with herbicide and the quality of the sward reduced. Ironic.

Oh, and phytoestrogens are a female sex hormone. Separate research suggests that plants use them as part of their natural defence against the overpopulation of herbivore animals by controlling fertility.