Fertility considerations when feeding clover to livestock

Red and white clover contain phytoestrogens (plant compounds) that mimic oestrogen and can affect reproductive function in livestock. Their impact is particularly significant in ewes during breeding periods and should be carefully managed.

By carefully managing red and white clover intake, especially around breeding periods, you can significantly reduce the risk of infertility in livestock.

Strategic feeding, monitoring and timely dietary adjustments ensure the health and productivity of breeding stock.

Phytoestrogens can disrupt the reproductive processes in female livestock, especially ewes.

Red clover contains higher concentrations of these compounds, and stressed white clover can also pose a risk.

• Avoid feeding red clover to breeding ewes for at least six weeks before and after tupping
• Limit white clover in the diet during breeding to avoid reduced ovulation and oestrus delays
• Apply the same restriction to stressed white clover, as its phytoestrogen levels can also increase

• Red clover silage is safe for use in breeding cows
• Direct grazing is less common, but it should be monitored if practised

• Fertility issues may not show outward signs
• Use reproductive assessments detect potential problems early

Clover disease describes the suite of fertility problems caused by high-phytoestrogen clover. These are:

• Low lambing rates
• Uterine prolapse
• Difficult lambing
• Uterine inflammation and secondary infections

The infertility is usually reversible within a month if clover is removed from the diet.

Visible symptoms such as vulval swelling and enlarged mammary glands may occur in some breeds.

Long-term consumption of high-phytoestrogen clover can lead to irreversible reproductive damage in ewes, even if they appear to cycle normally.

White clover presents a lower risk, but caution is still needed as, while it contains lower phytoestrogen levels than red clover, overfeeding or stress conditions can elevate levels.

This can lead to reduced ovulation and delayed oestrus in ewes. Monitor dietary inclusion, especially during breeding seasons.

Male livestock are less sensitive to phytoestrogens and studies show no significant effect on ram or bull fertility.

Breeding cows are less commonly grazed directly on red clover, and red clover silage does not negatively impact fertility and can be a valuable feed.

However, reproductive performance should still be monitored closely to ensure overall dietary balance supports fertility.