health & science

Celebrated brothers turn brains to dairy problems

Small fleets of robots cleaning up cow poop, fertiliser travelling at the speed of a jet plane, a computer-simulated rumen. Two eminent New Zealand scientists - who happen to be brothers - are applying their brains to finding high-tech solutions to farming pollution.

The board of Fonterra didn’t know the clever American inventor they were about to meet was really a New Zealander. But Ian Hunter, an engineering professor at MIT in Massachusetts and long-time resident of North America, felt comfortable as soon as he met them.

The dairy co-op’s directors were on an international tour when a management consultant suggested they meet Hunter at the office of a company he founded, electric vehicle enterprise Indigo Technologies. “I walked into this room with all these wonderful Kiwis, many of them farmers, and immediately felt at home,” says Hunter. “They said, ‘We’d like to do something with you, can you think of things we might do together?”

Hunter has been thinking of ideas ever since, from sheep dog-sized, cow patty-collecting robots to climate-friendly ways to dry milk powder. After a long and successful career in mechanical, chemical and bio-engineering, he decided about 10 years ago to only work on projects whose primary objective is, in his words, “making the lives of animals and humans on the planet better”.

He spent almost a decade working in “stealth mode” with others from Indigo, devising an electric vehicle with an in-wheel motor, an innovation designed to make EVs so light and energy-efficient that they needn’t plug into an electricity grid (grids that are often still powered by fossil fuels). Founded by Hunter in 2010, Indigo only revealed its design to in April. Now, Hunter is keen to apply his brain power to farming, which he sees as the next major climate issue after transport. He has a large laboratory at his house, and runs another, equally large one at the “office” - MIT’s Bioinstrumentation Laboratory. Since MIT spawns a new patent roughly every time you blink, he gets to hear about lots of potentially useful new technologies. “I’m hoping we can bring some of the MIT innovation style to bear on some of Fonterra’s business,” he says.

The deal is that he and Fonterra will co-invest and collaborate on farming technologies with a sustainability bent. Fonterra has access to farmers who can trial prototypes and, hopefully, eventually, use the finished products. Hunter hopes the project will result in around two start-up businesses in New Zealand a year, for the next five years.

To scientist Ian Hunter, pollution problems are engineering problems. Photo: Supplied

Because he’s not a consultant or employee of Fonterra, Hunter is free to state the co-op’s challenges in terms you might not find in a dairying brochure. “I’m a Kiwi and Fonterra is the largest company in New Zealand and I hate to say it, but it is probably one of the largest polluters in New Zealand,” he says. An average cow makes 100kg of methane (a greenhouse gas) a year, he says. Multiply that by every cow on the planet, add the nitrates lost to water and the other greenhouse gases produced and, well, it’s a steep challenge. But having these issues “creates an opportunity,” he says. “The wonderful thing about New Zealand dairy is [cows] are free range,” he says. But being outside makes the clean-up harder. “If the herd is in a shed, it is really easy to pick up the urine and cow dung and manage it, whereas when you have cows out on farm, the urine is highly disruptive to the grass and soil.”

This is where the robots come in. The first concept lined up to be tried on a New Zealand farm is an energy-efficient, light robot, which Hunter plans to have zooming about a paddock in a pilot trial in the next 12 months. While he won’t reveal what it will look like yet, he says MIT has a design for the correct kind of robot, which can already jump and flip, though not, yet, tend a cow herd. After further tweaks and testing, Hunter hopes small fleets could one day potter about farm pastures, gathering excrement, neutralising urine patches and delivering precision doses of fertiliser directly to grass roots - after first conducting soil tests to see what nutrients are missing.

The robots would “act as guardians of the herd”, he says, “fussing around in the paddocks picking up cow dung, moving it to a bioreactor that we will have in one corner of the paddock ... You wouldn’t want a human hovering around the rear of a cow picking up dung but it something a robot is quite happy to do. If we can do it, probably we can convert that cow dung into stored electrical energy,” he says. “We need to verify it experimentally, but it looks feasible that we could generate enough electrical energy to run all of the farm equipment and get away from tractors having internal combustion engines.”

Biogas from the manure, combined with solar energy, could charge the robots twice daily via a wireless flash charge (“we already have the technology for that,” says Hunter). The clean energy could also dry any milk that was going to be trucked off and sold as milk powder. Drying milk on the spot would remove the need for transporting heavy liquid milk by road for drying by coal-fired boilers, saving energy and fuel. The water extracted from liquid milk could be re-used on the farm for irrigation, he says.

"You wouldn’t want a human hovering around the rear of a cow picking up dung but it something a robot is quite happy to do."

Hunter’s MIT profile picture shows him looking a little like Dr Seuss’ Lorax, with a plush moustache and rounded cheeks. But if the Lorax’s style of environmentalism is simple - replant the trees you cut down to make stuff - Hunter’s style is more like The Jetsons-with-dairy-cows. To him, pollution problems are engineering problems. “The cow we can think of as a machine that consumes grass and produces milk, but unfortunately also produces methane and a huge amount of urine and cow dung,” he says. “Can we imagine a future where the farm is a closed ecosystem ... Where the net output is not pollution, but milk, with such a low level of pollution you can regard it as a sustainable material?”

Hunter is brimming with other ideas. One is using graphene technology developed by a young company at MIT to separate the urea from water in cow urine. It isn’t his technology, but he hears about such things. The urea could be re-used as fertiliser, and the water used for irrigation.

Then there’s a needle-free drug delivery system he and his team at MIT developed. It fires a substance into the body at around the speed of a jet-plane, so medicine can shoot through a tiny orifice, smaller than the tip of a hypodermic needle. It could be used to administer veterinary medicines to a cow, he says – and a robot might be able to do it. There’d be no risk of a needle breaking, if the cow moved quickly. Or, the rapid injections might be used to administer precise doses of fertiliser directly to the roots of grass – rather than into the soil, where excess nitrate that the grass doesn’t take up can flow into waterways.

There’s one problem he can’t think how to solve with emerging technology. Short of robots leaping into the air to catch each cow burp, there’s no easy answer to livestock’s methane, short of fewer cows. The question of methane from cows’ rumens is currently causing conniptions in Parliament, following the Government’s attempt to set reduction targets in the Zero Carbon Bill. But Hunter know someone who might help.

He has roped in his brother, the equally eminent Peter Hunter, of Auckland University’s Bioengineering Institute. Peter Hunter’s group has already done world-leading work building computational models of human organs. They have a working virtual human heart, skin, lungs and gastrointestinal tract. Now they want to build a computer-simulated rumen, the organ that digests grass and produces a cow’s methane.

In humans, these sophisticated models help test and identify medicines and other treatments before they go to live trials. In cows, Peter Hunter hopes, a virtual rumen could speed up and cheapen the hunt for a methane vaccine or methane inhibitors. Animal trials cost time and money, and can end in frustration if they reveal, for example, that a feed supplement doesn’t work after all, or cuts methane but increases some other greenhouse gas. A computational model could help researchers be “cleverer” about the solutions they target, says Peter Hunter. Eventually, a full working model of a cow, and a sheep, would be useful to have, if New Zealand wants to keep its economy hitched to farming animals, says Peter Hunter.

He and his team proposed building a rumen model years ago. But they struggled to find funding – until Ian Hunter met Fonterra’s board. While the dairy co-op has not committed to funding a computer-rumen, it has given the team a year-long grant to study how rumen microbes work. The fate of the bigger project will be decided soon.

Meanwhile, Ian Hunter will be refining his care-robots. Aside from muddy, bumpy paddocks, the major obstacle for deploying robots in dairying is cost. Right now, Hunter admits, most robots are “fearfully expensive”. Over the next decade or two, he hopes to be part of an effort to translate the robot into a low-cost format.

He is already doing the calculations. If the first pilot goes well, he wants to expand the robot trials to many more farms, which Fonterra is helping him find. But how many robot helpers does a herd need?

“We’re not imagining one robot per farm, there’s too much to do,” he says. If each cow produces 30kg of dung a day, 50 cows per robot might be manageable, he reckons – making a fleet of six robots for 300 cows, or 10 robots for a farm with 500 head of cattle. As well as being cheap, they’d need to be non-threatening to cattle, to avoid getting a hoof in the motor. Hunter hopes they’d be non-threatening to farmers, too. “We’re hoping to make life much more pleasant for the farmer,” he says. “The last thing they want to be doing is rushing around spraying urine to neutralise it, or picking up cow patties.”

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