EARLY LAMBING LIFTS SCANNING Shifting lambing date forward is another strategy designed to reduce the impacts of the drought. In a normal season the Sherlock’s Romney-based flock lambs from late August, but this year the mixed-age ewes started three weeks earlier. Jon says mixed-age ewes were mated from March 6 and the two-tooths from March 31. “In 2018 we mated 400-500 of our older ewes a couple of weeks earlier and they scanned at 176% while the other later-mated ewes scanned at 150%, so we thought we’d push all the mixed-aged ewes forward if it looked like we were in for another dry season.” This year the flock scanned at 165%, though the result was dragged down by the two-tooths, which scanned at 142%. Jon says this year’s lambing result may determine whether an earlier mating becomes a permanent feature. Fiona says lambing in early August may also be a better fit for the farm’s pasture growth curve, and should make it easier to hit the 29kg LW target for lambs by December if kinder winters are becoming the norm. Hitting this target has proved challenging over the last two years because of the dry conditions. “Because we are mainly a store operation, weaned lamb weight is our key profit driver,” Jon says.
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Otorohaea Sheep Performance 2015-2019 Year
Scanning %
Lambing %
Ave weaning weight
kg weaned lamb
2015
164
135%
27.4
98,387
2016
171
136%
27.6
111,338
2017
179
136%
26.2
106,922
2018
169
135%
27.0
120,015
2019
151
121%
28.1
101,493
Total average weaned lamb weight over the ten-year period prior to 2014 was about 85,000kg/year, but the Sherlocks want to lift this to 137,000kg. Jon says getting lambs to 29kg by weaning would enable the sale of a higher percentage off mum “and that’s not easy to achieve on hard hillcountry”. Average daily lamb growth currently sits at about 260grams from birth to weaning. Otorohaea’s lighter stocking rate suits the contour and gives the ewes the opportunity to feed their lambs well. Ewes are pregnancy scanned in June and set-stocked from mid-August. “We try to keep things as simple as possible at this time,” Jon says. “Normally before set stocking we’d rotationally graze the single-bearing and multiple-bearing ewes together, but if feed’s tight we can separate the twinners and give them priority. “Usually we’d set stock the twinners at a rate of two head/ha lighter than the
singles. This year, because of our lighter stocking rate, everything is set stocked at the lower rate of 7-8/ha.” A key aim is to get pasture covers to 1800-1900kg DM/ha by May 1 and 1500kg DM/ha by mid-August. Feed demand this July was about 10.5kg DM/ha/day. Jon says a sample group of ewes is weighed at key times, including mating and weaning. “But in future we will move towards a condition scoring system because it seems to offer more advantages as a management tool.” The Sherlocks have tried experimenting with different brassica crops on the Kerr Road farm but the results have been variable in dry years. “Last year we planted 15ha of leafy turnip as a summer crop, but we only got one and a half grazings out of it.” In future they may try aerially oversowing legumes into pasture in tandem with a deferred grazing programme.
Country-Wide
October 2020