ON FARM SHEEP The case for clover Yvonne Hams, Vivonne Bay,SNAPSHOT:Robert Hams, Ron and S S outhern Australiansheep producersare benefiting fromnew knowledge• Analyse each paddock to1. Understand the issueassess farm-scale prevalenceof problem clovers. Kangaroo Island, SA on an old issue, with MLA 2. Graze strategically funding research identifying • Avoid grazing ewes on problem sub-clover cultivars oestrogenic clovers before or in pastures. during mating, as clover can cause temporary infertility. Clovers are an important feedbase • Avoid long-term exposure for many producers, but older, of ewes to large amounts of high-oestrogenic varieties can oestrogenic clovers, as this can cause havoc with flock fertility. cause permanent infertility. This Area: 900ha arable A three-year producer cumulative effect can occur over demonstration site (PDS) is two to three years’ exposure. Enterprise: addressing declining ewe fertility • Reserve high-oestrogenic Lamb and wool production from clover-based pastures. clovers to finish terminal lambs or The ‘Good clover, bad clover’ cattle, which are not affected. Livestock: • Graze weaner and young 4,000 ewes and weaners project aims to increase producer awareness of potential issues ewes on the least oestrogenic Pasture: from problem varieties and give pastures available. Sub-clovers producers practical tools to • As the plant senesces (dies off), manage pastures and improve isoflavones break down and Soil: animal health. Due to conclude in plant material becomes safe for Ironstone rubble over clay late 2019, the two-and-a-half-year grazing ewes. project is funded by MLA and • Avoid cutting hay and silage from Rainfall: MacKillop Farm Management oestrogenic clover paddocks, 550mm Group with in-kind and because fodder cut at the ideal sponsorship support from time before clover has senesced LESSONS SheepConnect SA and Natural is still problematic. Resources South East. 3. Manage pastures LEARNED The project has revealed that • Dilute clover-based pastures oestrogenic pastures are more with newer, non-oestrogenic > Oestrogenic clovers are a prevalent than initially thought. potential cause of low lambing clovers or other pasture species. percentages. A survey of 160 producers • Develop a long-term strategic > The clovers can be safely grazed showed most were unaware of the spraying and grazing program by rams or finishing prime lambs presence of oestrogenic clovers, with an agronomist to prevent for sale. with 85% never having undertaken clover seed-set and reduce the > When oestrogenic clovers are a visual assessment or laboratory seed bank. completely dried off, they may be analysis of their clover pastures. • Buy certified clover seed to grazed by ewes. ensure it does not contain The good news is there are older varieties. management strategies available • Be aware that purchased hay to producers, including the or silage for feeding ewes following tips: could contain high-oestrogenic clovers. ■ Mick Taylor, MLA E: mtaylor@mla.com.au 27