The latest New Zealand Grassland Association (NZGA) conference was held in Oamaru in spring. A highlight for me was hearing from Gundy Anderson, who farms Bog Roy Station in the Mackenzie District with his wife Lisa. He explained the production changes that have occurred on his farm over the last 16 years. In 2008 the farm was under financial, policy and physical pressure with hieracium (hawkweed) from overgrazing and a decline in hill and high-country pasture yields.

This combination was creating emotional pressure on himself and those around him. The catalyst to transform the farm came from a visit to my office, when Lisa, working for Merino Inc. at the time, came to ask about some of our work. Gundy saw the hand-out we had just used for the Bonavaree field day in Marlborough and had a question for us; “Could the hand-out be used in his 420mm rainfall environment?”

We discussed his stock policy, and determined he had limited feed supply in summer due to a lack of late spring and summer rainfall. Consequently, he ended up with small store merino lambs at a time when few people wanted them. He determined this was not a sustainable business model and was looking for options.

I subsequently visited the farm and confirmed that lucerne grew well in the environment. The district is well known for growing lucerne but at that time on most farms, including Bog Roy, it was predominantly conserved as hay or silage to feed ewes through the long winters. Cutting was at 10% flowering, with ewes and lambs looking on enviously as the leafy green herbage was diligently baled. They scavenged drying annual grasses that were going to seed, leading to overgrazing on the hills. If lambs were lucky, they got a green pick post weaning on any lucerne regrowth, but this was not common due to the summer dry.

We used the results of our research at Lincoln University to challenge this traditional lucerne management style. Our research showed it did not need to flower in the spring, only requiring a rest in autumn. I advised Gundy to start ewes and lambs on lucerne two weeks after lambing when it was about 15cm high. He only had large paddocks, so he started mobs of 700 ewes and lambs on a six-paddock rotation.

Rotationally grazing such large mobs of merinos on lucerne was a leap of faith for both of us. Fortunately, under Lisa’s watchful eye, Gundy made it work.

We demonstrated that the lucerne was more productive than his grass-based pastures, and this provided the evidence for an increase in dryland lucerne from 30 to 350ha. The two years of ryecorn to break in the ground provided cheaper winter feed and paddocks were subdivided to transform the grazing management. Ewes and lambs were moved around the lucerne during lactation rather than being scattered across the hills.

After about fi ve years of expanding the dryland lucerne area, and taking on debt to do so, the accountant asked a typical accountant’s question: “But is it profitable?” To be fair, neither Gundy nor I knew, we just knew it was working from an animal performance perspective. Answering that question required data, so Gundy enlisted the help of Marlborough vet Pete Anderson and the StockCare recording programme.

It was this data, recorded over many years, that had some eyes popping as it was presented in Oamaru. Lamb production has lifted from 91 to 163 tonnes per year and the associated income from 200 to 700k. Tellingly, Gundy explained that for him, the ability to have large numbers of animals on the area of high performing legume-based forages, meant his hill country has recovered.

He highlighted the hieracium is all but gone and the annual legumes now provide quality feed for the ewes when they are removed from the lambs on lucerne at weaning. Such ecological service components of the system are not always immediately obvious nor easily measurable, but they are recognised and incredibly satisfying for landowners.

In terms of animal performance, the numbers are impressive. Mixed age ewes are now consistently 66kg at mating and two-tooth mating weight increased from 52 to 61kg over 11 years. Pregnancy scanning averages 167% for mixed age ewes and increased from 113% to 154% in the two tooths. Lamb wastage (scanning to weaning), for mixed age ewes has decreased each year to 15% in 2023. The wastage in two-tooths is negatively related to their weight at set-stocking, so feeding light stock is a now a priority. This has reduced their wastage from 34 to 21%. Since 2016, pre-weaning lamb growth rates have averaged 286 grams per head, per day (g/hd/d) and weaning now occurs at about 80 days - 40 days earlier than in 2008.

The consistency of pre-weaning growth rates has coincided with the transfer of water from Lake Benmore that enabled the development of two: centre-pivot irrigators. Under these are legume dominant pastures. Identifying the optimum mix required some trial and error. The result being 9kg per hectare (kg/ha) of lucerne with 4kg/ha of prairie grass and a splash (1kg/ha) of herbs and white clover added to ensure legume dominance. Being a merino property, wool is still an important contributor to income and total wool production has been relatively stable at 32,000kg per year and 18 microns. Cattle numbers initially dropped during the dryland development because they provided a buffer during dry years. They are now higher than they were at predevelopment with 186 in-calf cows and a target of 200. The Hereford pregnancy rate has averaged 94%, and from 2018 to 2023 the weight of calves sold has increased from 22T to 46T.

On Bog Roy Station the system now has greater resilience. The farmers are confident they can cope with the range of climatic conditions it experiences, now and into the future. The main change has been in grazing management with an emphasis on the legume components of the farm system. After 16 years the changes seem simple, but there are always setbacks. Gundy highlighted the impact of a foot rot outbreak in 2021, and a Porina caterpillar attack in 2019, which resulted in the loss of all the permanent grass-based pastures under the pivots.

He finished his talk by explaining why this transformation has been successful; the trust between farmer, vet and scientist, all working together to solve a problem.

It is what New Zealand agriculture is renowned for, what we are good at. Next year the conference is in Hamilton and I look forward to seeing how agricultural science has been applied in that region to adapt to the policy, environmental and climate issues that have challenged their farm systems.