ON FARM SHEEP FEEDBASE f Making good pasture investments The first indication there Oestrogenic clovers – the bad clovers –balansa. It seems to be going alright was a problem on the are Dinninup, Dwalganup, Yarloop andbut we had to reduce stock to be able Hams family’s Kangaroo Geraldton. These older varieties containto do it. Island was when lambing high levels of the isoflavone formononetin,“The new cultivars that we’ve sown are percentages dropped to around which leads to fertility problems in ewes.i producing better quality and quantity of 25%. The ewes were in good The effect is cumulative, so lambng feed, but we’ve only had stock running percentages will continue to drop fromon it for a year because we had to let condition and, while the pastures one year to the next. looked fine, the problem the seed bank establish. was soon identified as being “Wethers may also experience problems“In the early days, we just managed oestrogenic clovers. on oestrogenic clovers over time due tothe oestrogenic pastures we had by enarged bulbo-urethral glands, whichlD running cattle or wethers on them, That was 38 years ago. ma lead to death,”yavid said. rather than trying to renovate them. At the time, Primary Industries and “Wethers to be sold as prime lamb canWe’ve also run our older ewes on Regions South Australia researchers be run on the oestrogenic clovers them and accepted lower lambing David Little and David Woodard were because they aren’t on the pasture forpercentages in that mob. The working on a research project on long enough to have any problems. oestrogenic clovers can also be grazed renovating oestrogenic pastures on “Ewes may fail to conceive or abort beforesafely by ewes when the grass is problem and mapped the oestrogenicKangaroo Island and they identified the full term.C completely dry.” ■onception rates will vary and clovers on the Hams’s farm. a wide spread of lambing time may occur withinthe flock. Rams are the only sheepRobert Hams “The percentages were pretty ugly,” notaffected by the bad clovers E: rjhams@bigpond.com . David Woodard said. David Woodard, PIRSA “Pastures can be renovated and Rob T: 0417 803 525 “The paddocks ranged from 4% to Hams (pictured) is doing a good job E: david.woodard@sa.gov.au 59% oestrogenic clovers. We work on renovating his.” anything above about 20% as posing a Lyn Dohle, PIRSA risk. Back in those days on the Hams’sRob said the process of renovating the T: 08 8553 4999 place, we found that out of thirteenaffected pastures takes several years. E: Lyn.Dohle@sa.gov.au paddocks, nine were high or very highThe enterprise’s lambing percentages are now back up to around 80%. Head to sheepconnectsa.com.au and only two were totally safe.” and search ‘clover identification’ David Woodard returned to the Hams’s“We began renovating them by cropping farm in October 2018 to conduct a the paddocks two years in a row,” he said. field walk organised by Agriculture So far 180ha has been renovated with Kangaroo Island (AgKI), MacKillop FarmRob admitting the significant investment Management Group (MFMG) and MLA, and taking those paddocks out of grazing who have partnered on a project calledrotation does slow the process. ‘Good clover, bad clover’. The project“We sprayed out the clover at seeding will work closely with local producersand then sprayed again over the top to determine what constitutes good of the crop. Then in the third year, we and bad clover and how to implement knocked the paddock again before effective management of clovers. reseeding it with two sub-clovers and 26