Putting precision into lambing
06 September 2018
Tim Leeming is a long-time advocate of running multiple-bearing ewes in small mobs at lambing.
His triplet-bearing ewes typically lamb in mobs of 8–20 ewes, while twin-bearing ewes lamb in mob sizes of 45–55. Single-bearing ewes can lamb in mob sizes of up to 800.
Tim and his wife Georgie collect significant data on their lambing mobs, which they provided to the MLA-funded lambing density research project. They farm on 1,530ha at Pigeon Ponds in south-west Victoria and run 7,500 breeding ewes in a 600mm rainfall zone.
The smaller the better
Tim has been scanning for multiple lambs since 1995 and has differentially managed single- and multiple-bearing ewes for 20 years.
“There are a lot of variables that can come into play but, generally speaking, the smaller your mob sizes for multiple-bearing ewes in our part of the world (higher rainfall, higher stocking rates), the better your lamb survival,” Tim said.
“That’s shown by 20 years of my diaries and spreadsheets, which show if you can take a multiple-bearing mob size of 150 back to three mobs of 50 each, you’ll probably pick up 10% extra lambs, everything else being equal.
“My records also show no benefit to smaller mobs for single-bearing ewes, but I’ll still put them in a protected paddock and give them half the amount of feed as a twin-bearer to protect them from dystocia.”
Tim has changed several ewe-management practices in the past 20 years, with shorter joinings being the main one.
“We’ve gone from a six-week joining 20 years ago, down to three joinings of 17 days each, with 20-day breaks in between,” he said.
“Last year, out of just under 7,000 ewes joined, we had 1.7% dry. The year before we had 2.1% dry, so even though it sounds risky, it’s not.
“The end result is that we’re not lambing over a longer time than we used to 20 years ago, but we’re using scanning technology to be more strategic in planning that ‘end part’ of the process – lambing.”
Tim said that by keeping joining tight and identifying foetus size with ultrasound, he can segment lambing so his ewes get the best paddock, shelter, nutrition and mob size to maximise lamb survival.
A matter of strategy
The Leemings split their best lambing paddocks using electric fencing reels and tread-in posts. Paddocks of 15ha may be split into three or four small paddocks.
Ewes on a 17-day lambing cycle go in a couple of days before lambing and leave a day after the last lamb is born.
After lambing, the ewes and lambs go back into a big mob and are moved to a more exposed paddock.
“That enables us to preserve the pasture they lambed on and even build it up with some urea or gibberellic acid during the 20-day break, before we bring in the next bunch of multiples on the next 17-day cycle,” Tim said.
“It sounds like a lot of work, but it just comes down to planning and maintaining your calendar entries.
“It does require using scanning technology to its utmost, but it’s worth it,” he said.
The Leemings stock well above industry rates – eight ewes/ha in a 600mm rainfall zone – and in 2016, they achieved 88.5% lamb survival across their mature-aged ewes, despite experiencing the district’s wettest winter on record.
Last year, Tim and Georgie achieved 90.8% survival after having another 1,000mm of rainfall.
Put precision at the end
Tim said 90–95% of ewe and lamb mortality occurs in the last few days of pregnancy and the first few days of lactation, but this is the stage where ewes are usually left to fend for themselves.
He would like to see more sheep producers embrace what he calls “precision lambing”.
“Croppers have embraced precision agriculture and so have sheep producers to some extent, in that we now use feed budgeting, condition scoring, and differential nutrition allocation to twin-bearing and single-bearing ewes,” he said.
“However, we still get to a point where we put the pregnant ewes in the lambing paddock, say ‘good luck’ and hope for the best.
“Croppers don’t get to harvest and say, ‘well, we put all this effort into sowing and growing, now we’ll get the old tow-behind, busted header and blow half the grain on the ground’.
“Like them, we need to put precision right at the end, where we actually ‘harvest’ our product.”
Watch this video which shows how the Leemings set up paddocks for precision lambing.
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