Nutritionist > Equine

Zearalenone (ZEA)
Zearalenone often occurs with DON in naturally contaminated cereals, straw and forage as both are actually produced by the same fungi.. Zearalenone is responsible for reproductive disorders due to its oestrogenic effect at high concentrations. ZEA is not really toxic, even though it is biologically potent as it is a non-steroidal oestrogen, being very similar to 17?-oestradiol. ZEA is produced by Fusarium species which are regular contaminants of cereal crops worldwide.

Although the importance of the detrimental reproductive effects of ZEA in pigs and cattle are well known, limited information exists for horses. When the effects of various concentrations of Zearalenone and its derivatives on granulosa cells from the ovaries of cycling mares were observed, it was found that these mycotoxins could induce follicular atresia. The granulosa cells were cultured in vitro and it is hypothesised that these mycotoxins may be implicated in reproductive failures of unknown cause in mares.

However, when zearalenone was fed to mares for 10 days, to mimic 1ppm concentration in feed, there was no effect on ovarian activity, however these levels are also ineffective for very sensitive species such as pigs.