Third-generation sheep farmers are adapting to climate change on drought-prone hills. Mike Bland reports.

North Waikato farmers Jon and Fiona Sherlock are fine-tuning their sheep policy in an attempt to reduce the impacts of increasingly dry summers.

The Sherlocks run Otorohaea, a 660-hectare (575ha effective) hill country farm at Waingaro, west of Ngaruawahia. Otorohaea has about 50ha of rolling ash contour and the rest is medium to steep hill, most of it Land Use Capability Class 6e and 7.

Jon, a third-generation of Sherlocks on the farm, says the exposed hill country is challenging to manage at the best of times, but a double drought hasn’t made life any easier.

“Because of the farm’s steepness it feels the drought more than easier-contoured properties, and it takes longer to recover.”

Annual rainfall is typically about 1300mm, but the farm’s received much less than this over the last two years. So the Sherlocks have front-footed their approach to drought management.

“After the 2018-19 season we decided we had to come up with a strategy to cope with very dry years,” Jon says.

“Drought comes with a cost, so you have to put a plan in place and make decisions early.”

Otorohaea is split into about 70 paddocks averaging 2.7ha on the rolling-medium hill and 13.5ha on the steep hill. Sheep will always be a big part of the operation because of the steepness of the country. Coming out of a drought it has a 72:28 sheep to cattle ratio. Most lambs are sold as stores in early December at 27-29kg liveweight (LW).

This year Otorohaea wintered about 2550 mixed-age ewes and 650 two-tooths, along with 190 R1 heifers and 53 R2 heifers.

Jon says ewe numbers are down due to the drought. In a more typical season the farm would winter about 3500.

“In the summer of 2018/19 we had to sell some capital stock, but we probably could have maintained numbers if we had started feeding sheep nuts earlier.”

The plan for the next summer was to buy in up to 500 ewes – preferably with strong genetics – between December and February if feed conditions allow, “and then sell the bought-in ewes and/or cull ewes if it starts to get very dry”.

Jon says the biggest challenge is keeping ewe weights up to minimise the impact on next season’s production.

With Fiona, manager Graham Hayde and farm consultant Peter Fraser, he has made a number of tactical decisions designed to combat drought on Otorohaea. These include flexible lambing dates, feeding out supplement to the mixed-age ewes, and grazing ewe hoggets off-farm.

Since 2016 about 800-1000 ewe hoggets have been shifted from Otorohaea to the Sherlock’s other farm near Naike, bought in 2016.

Ewe hoggets are mated only if they reach a minimum of 40kg.

“They haven’t been mated for two years because we didn’t see the feed in front of us,” Jon says.

“We’d much rather see a 62kg two-tooth coming home than a lighter, mated hogget.”


Jon says a 62kg mating weight for two-tooths and 65kg for mixed-age ewes are key targets. He reckons this is a good match for the farm’s steep contour. A 65kg ewe is an efficient feed converter while being mobile enough to handle the hills without causing damage.

Records taken by him and his father, Rory, show a strong correlation between mating weight and scanning results. In 2019, following a drought, the average mating weight was 57kg and ewes and two-tooths scanned at 151%. In 2007 they averaged 62kg and scanned at 179%.

In 2008, another bad drought year, the ewes averaged only 44kg and scanned at a disappointing 114%.

Jon says the 28% drop in scanning between 2017 and 2019 shows the real cost of the drought in terms of lost lambs.

He says the farm is targeting a consistent lambing of 140% docked.

“We haven’t cracked that yet, but we were hitting about 135-136% in the years before the drought.”

Last year, after the 2018-19 drought, the farm achieved only 121%.

Jon says the 15% drop in lambing drove the decision to start feeding supplement as soon as conditions started to dry up this year.


This year the Sherlocks fed about 40 tonnes of sheep nuts at a cost of $750/tonne.

The pellets were fed from a spreader towed by an ATV.

“Sheep nuts are the only practical option for our contour,” Jon says.

“At around 75c/kg drymatter (DM) and a total cost of $30,000, the sheep nuts were not cheap, but we decided to take the hit and go early so we could maintain ewe condition”.

He believes the investment will pay off.

“A 15% lift in lambing equates to about 480 extra lambs. At $90/lamb, that’s $43,000, which easily covers the cost of the feed. That makes sheep nuts look pretty good, especially when you take into account the better condition of the ewes.

If supplement is required again next season, Jon says they will look to reduce the cost by feeding maize.

Fiona says feeding sheep nuts helped lift morale during a very tough season.

“The ewes loved them and it made us feel good to know we were actively doing something for our stock.”

Grazing ewe hoggets “down country” on a liveweight gain basis is another option being considered by the Sherlocks to simplify the system at home and to spread their climatic risk.

Ewe hoggets are currently grazed on the Kerr Road farm but Jon says it’s difficult to achieve good growth rates consistently in the North Waikato, especially if it’s dry.

“If it works, we’d like to send about 850 ewe hoggets to an area where they will achieve good mating weights, then bring them back here after weaning their lamb.

Grazing ewe replacements off-farm also gives us the opportunity to increase ewe numbers on Otorohaea and bull numbers on the Kerr Road farm.”

A 62kg mating weight is a key target for two-tooth ewes on Otorohaea.


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.

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.

Jon says other options for the steeper contour are also being considered, including planting trees for timber or carbon credits.


Jon Sherlock says the flock’s strong

Romney base provides the hardiness to handle Otorohaea’s steep hills.

The flock also has some Finn and Coopworth genetics and, while the Sherlocks may consider crossbreeding in future, Romney will likely remain the predominant breed.

Jon says sheep fertility has improved over the years and he is confident the 140% lambing target is achievable.

“We might not get much higher than that. A 150% lambing would probably be hard to achieve for this type of country without dropping stocking rate. It’s all about finding a balance between lambing percentage, stocking rate and pasture demand.”

Facial eczema (FE) is a major issue in the region and the Sherlocks source FE-tolerant rams from the Waimai Romney Stud, Te Akau.

But, Jon says, they still remain vigilant for signs of FE. Last year he noticed a dozen sheep in a mob of ewe hoggets showing suspect symptoms.

“Over the years the flock has built up a strong tolerance for FE, but we have to remember that tolerance is not the same thing as resistance, and we can’t be complacent.”

Viral pneumonia is another issue, again mostly in the younger sheep.

Jon says steep hills and often dusty conditions make it difficult to combat.

Fiona says they try to minimise stress on the sheep as much as possible.

“We don’t wean and shear at the same time, and we dampen down the yards before working in them.”

Jon and Fiona Sherlock took over Otorohaea in 2014.


After taking over Otorohaea, Jon and Fiona sold the breeding herd and switched to a heifer trading policy.

They initially ran older heifers but now they buy in about 125 R1-year heifers in autumn and aim to finish them after 18-20 months on the farm. Most go before Christmas at about 240kg carcaseweight (CW).

Jon says the younger heifers are better for the hills than heavier stock, which can cause erosion damage.

But the Sherlocks aren’t committed to selling prime if feed gets short.

‘The theory behind the heifers was that they give us flexibility,” Fiona says. “If it gets dry, they can go.”


Taking over the family farm wasn’t always the number one goal for Jon Sherlock.

He and wife Fiona had successful careers off-farm before returning to Otorohaea. But when the opportunity to buy the farm arose six years ago they decided it was what they wanted to do.
Fiona, who was raised on a Hawkes Bay orchard, met Jon at Massey University where they both studied agricultural science.

In 2004, after a long stint working overseas, the couple teamed up with farm consultant Peter Fraser to establish subscription-based livestock market information service iFarm, which was later sold to NZX Agri.

They returned to live on Otorohaea in 2009 and started farming it in 2012. In 2014 they set up a company with Jon’s brother Ric and sister Toni to buy the farm from Jon’s parents, Rory and Sue, who had run the farm since taking it over from Rory’s parents in the mid-1970s.

“Dad was ready to wind down a bit. Fiona and I were keen to take over and we put a lot of thought into whether we were going to do it on our own account or not.”

Jon’s siblings both had off-farm careers – Ric is a geneticist at Livestock Improvement and Toni is an employment lawyer – and weren’t interested in physically running the farm themselves. But, like Jon and his parents, they had strong emotional ties to the property and were keen to keep it as a base for family.

So the siblings set up the limited liability company Otorohaea Ltd, taking up equal shareholdings to buy the farm and finance future expansion.

“We run a fairly formal board structure, and we officially meet about four times a year,” Jon says.

“Everyone brings different skills to the business, so there is a real synergy there.”

Fiona says the Sherlocks are a close-knit family, which helps make the system work.

Rory Sherlock is a director of the company but not a shareholder. He and Sue live in a new house built on the farm and he still helps out.

Jon says it’s a real bonus being able to call on his Dad’s advice when needed.

He says Otorohaea Ltd’s structure probably wouldn’t suit every farming family, but it does work for them.

“If Fiona and I had bought the farm on our own we would have been very restricted by debt. But this structure gives us the ability to expand and go for more scale.”

In spring 2016 the company bought another 450ha (375ha effective) hillcountry farm on Kerr Road, near Naike, a 25 minute drive from Otorohaea. This takes the total effective area to 950ha.

The Kerr Road farm is mostly medium hill, with some steeper slopes. Its gentler contour is well-suited to finishing bulls and grazing ewe replacements.

“We’ve struggled to get ewe hoggets up to good weights on the steeper contour on Otorohaea, and they’ve often played second-class citizens to the older ewes. Now we have the ability to shift them over to Kerr Road and get them growing.”

The plan is to mate ewe hoggets at Naike if they reach target weights, then return them to Otorohaea at weaning.

This year the Kerr Road farm is wintering 820 ewe hoggets and about 600 R1 and R2 Friesian bulls. The Sherlocks are still refining cattle policy on the new block, but the present system is focused on finishing bulls at around 30-months in November or December, averaging about 330kg CW.

Jon says rolling-medium contour on the Naike farm is split into 2-3ha paddocks, and further subdivision is planned.

He oversees the whole operation while also finding time for other commitments, including being a member of Beef + Lamb NZ’s farmer council.

Both he and Fiona also work parttime for Maui Milk, a large sheep dairy enterprise based in Taupo. Fiona is an executive officer for the business and Jon recently took on a general manager role, supervising two of Maui Milk’s farms.

Much of their work is conducted from home. They employ two managers to look after their farms – Graham Hayde on Otorohaea and Chris Kereopa on the Kerr Road block.

Graham has been on Otorohaea for over 15 years and Chris was hired last year.

Jon says their goal is to run a profitable and sustainable farming business that “fits the land”.

The Sherlocks have three children – Taylor, 14, Kate, 13, and Hayden, 11.

Jon and Fiona are quite happy for their offspring to build careers and experience off-farm, but if one does decide to return to the farm eventually they would be happy to hand it over to the fourth generation.


  • Jon and Fiona Sherlock, North Waikato
  • Farming 950ha effective
  • Otorohaea, Waingaro – 575ha eff.
  • Wintering (2020) 3200 ewes, 190 R1 heifers, 53 R2 heifers
  • Kerr Road, Naike – 375ha eff.
  • Wintering 820 ewe replacements, 325 R2 Friesian bulls, 200 R1 Friesian bulls and 36 R3 Friesian bulls
  • Store and finishing operation
  • Targeting 137,000kg weaned lamb