Oestrogenic sub clover pastures: identification and remediation

Summary

This project entitled - Maximising the reproductive potential of the meat sheep industry by eliminating high oestrogen clovers, more live lambs on the ground – is a two-stage, 3-year extension-focused project.

Sub clover is the dominant annual pasture legume in Australia with 42 million sheep grazing sub clover pastures. High levels of oestrogens in older varieties can cause ewe temporary and permanent infertility, dystocia and ewe and lamb mortality; this is sometimes termed Clover Disease. The number of ewes likely affected within the national flock is estimated by to be as high > 10 million. However, in spite of the magnitude of this issue, there are no current producer guidelines focussed on the problem, and producers and advisors often have minimal awareness.

During the first 12 months of the project (Phase I) the University of Western Australia (UWA) have engaged over 400 framers and industry representatives through talks, farm walks and clover identification workshops. In particular, the project team have visited a large number of producers in SA and Victoria in collaboration with David Woodard from PIRSA. The project team have disseminated pasture sampling kits and provided laboratory results to producers who submitted sample for analysis; follow up sampling will occur in phase two. In the first year of sampling 59% of samples were found to have oestrogen levels above the safe level and a further 25% were between four and nine times higher than safe levels i.e. highly potent.

The team have also commenced a farm renovation study at the UWA Future farm at Pingelly, WA. The next phase of the project will see the livestock side of the project commence focused on the physiological impacts on the ewe and the project team have planned activities in this space over the remaining two years. In summary, overall, these 12 months of activities have confirmed that high oestrogen pastures are common in southern Australia and that there is likely to be a significant impact on flock fertility. In WA, the team have been working closely with DPIRD and local farmer Tim Watts and plan to continue this collaborations throughout the remainder of the project.

The next steps for the project involve continued extension activities across WA, SA, NSW and VIC, additional sampling of sites with suspected presence of oestrogenic clovers and formulation of guidelines to manage oestrogenic clovers where they occur. Additionally, the project team will develop a Subterranean Clover Cultivars Guide as well as a teaching package for inclusion into University syllabuses and extension programs.

For further information on oestrogenic clovers and the ongoing project please contract:

Dr Kevin Foster

The University of Western Australia

P: 08 6488 2220

E: kevin.foster@uwa.edu.au