Cows as office workers, in cubicles
Eloise Gibson visited a Canadian feedlot in 2016 and found North American scientists grappling with the grass versus grain debate
My guide on my first visit to a feedlot is an affable young post-doctoral researcher named Martin Huenerberg. He drives me to a farm in Lethbridge, Alberta, the heart of Canadian beef country, where the thriving local barley industry makes buying grain for cows attractively affordable. Huenerberg is German and drives what might be Alberta’s smallest, reddest car. The car, perhaps misunderstanding its risk of being stolen in this truck-and-pickup-toting town, sports a super-sensitive alarm system that triggers every time we touch the vehicle. Huenerberg chews big, gummy, snail-shaped Haribo sweets as he drives me along flat, narrow highways, pointing out a potato factory and a grain processing plant. The climate here is good for feedlots. It seldom rains too heavily, so the penned-up cattle stay warm, but, because this is Canada, they don’t overheat.
We pull over at a small feedlot, one with just over 3000 cattle, a tiny operation compared to the intensive cattle mega-cities operating elsewhere in North America. Manure-booted cattle look up as we drive in, then return their steamy noses to the food buckets. He brakes in front of a large concrete bunker and plucks handfuls of food mix from various storage boxes to show me what the cows are eating. Around here, a typical feedlot diet might consist of barley and/or corn grain, barley or corn silage (made of chopped and fermented whole plants) and a supplement containing minerals, limestone (for calcium) and salt.
The silage is crucial. Just-weaned calves get a mix that looks like dried and mown grass with just a few kernels of grain. Next, they graduate to a 60/40 silage/grain mix and, finally, to a 90 percent grain diet, to quickly get them to slaughter-weight during the final four-six months of their lives. Cows need time to adjust to a high-grain diet — if calves switch directly to eating grain from grazing grass with their mothers they may gorge, bloat and, in severe cases, die, because their gut microbes are not acclimatised. Even when they are used to a high grain diet, they need about 10 percent fibrous, grassy food to stimulate their saliva and keep the rumen as close to pH neutral as possible, says Huenerberg.
Most feedlots around here have their own mills, where they try to crack the grain without making it too powdery. “You don’t want it too fine because fine [grains] are digested very fast,” Huenerberg says, “like a Mars Bar.” Mars bar-like food can produce acidosis, a gastric upset akin to severe acid reflux. This is not ideal for the cow, or the farmer. Cows with acidosis don’t gain much weight, and cows fed too little grassy fibre can also suffer liver abscesses, bloat and lameness caused by elevated levels of histamines in their blood.
As we cruise by the pens in the little red car, Huenerberg points out the cattle’s ears containing hormone implants. Feedlot operators in Canada often boost cattle’s weight using hormones, antibiotics and, less commonly, beta-agonists (adrenaline-like medications, related to human asthma medicines, which divert nutrients from an animal’s organs to its muscles). Constant doses of antibiotics, such as Monensin, seem to help cattle digest grain with fewer gastric upsets, making the animals more efficient at turning grain into meat. Beta-agonists are less widely used. One brand was pulled off the market after causing weight gain so extreme that cattle’s hoofs could not support them. “Sometimes in the past it was very, very aggressive and the animals got too heavy for their own feet,” says Huenerberg. But, typically, he says, feedlots take a “more balanced approach”.
Huenerberg splits his working week between researching cattle’s climate impact at Agriculture and Agri-Food Canada and a second job as a private consultant to feedlots. The first job is all about cutting cows’ emissions, the second involves working out what foods will help fatten cattle fastest, for the least cost, without making the animals sick. The two goals aren’t necessarily contradictory, though they are both incompatible with a long and active life for a cow.
You might think of a feedlot cow as an office worker sitting in a cubicle, next to a fully-stocked vending machine. As a lifestyle, it might not scream fulfillment, but as a weight-gaining, calorie-hoarding exercise, it works. A typical North American dairy cow makes around three times the milk of a New Zealand one, according to one estimate, and beef cattle gain weight faster, and are slaughtered sooner, than pasture-grazing ones.
All cattle are climate culprits, thanks to their methane-laced burps and other impacts, especially beef cows. But because a feedlot cow’s greenhouse emissions are spread over more kilograms of human food, they can – paradoxically – come out better on some lifecycle analyses of carbon footprint.
The reason for this is the same reason Huenerberg always recommends his farmer clients feed cows fibre: it’s their gut microbes, or, specifically, rumen microbes. The reason cows need fibre – and the source of most of their greenhouse emissions – lies inside their rumen, the largest of their four stomach chambers. The rumen is a mysterious, impressive organ that’s allowed cattle to carve out a niche on our dinner tables. It lets them create human food (meat, milk) from chewy, stalky plant matter that we weak-stomached Homo Sapiens could never eat.
The rumen is inhabited by a miniature megalopolis teeming with bacteria, fungi and protozoa, which work in teams to break down tough plant cell walls. An unfortunate by-product of this is that a wily breed of microbe, called a methanogen, has evolved to mop up the hydrogen left behind when other microbes break down cellulose. Methanogens turn the hydrogen to methane, which the cow belches out in a flow that increases just after it eats.
Methane is a sprinter, not a marathon runner, in the atmosphere. It peters out in around a mere 10 or 12 years, much sooner than a molecule of carbon dioxide, but while it is there it is much more powerful than Co2 at trapping heat. According to the latest assessment report from the Intergovernmental Panel on Climate Change, over 100 years its warming effect is 28 to 36 times higher than CO2’s. Over 20 years, it’s more like 84 times as strong. Methane ranks as the second most prevalent human-caused heat-trapping gas, after carbon dioxide, and is thought to be responsible for about 27 percent of the warming the Earth is already experiencing. Collectively, livestock make about a third of it, and no developed country has a bigger burping problem, proportionally speaking in its greenhouse ledger, than New Zealand does. Farming meat and milk has other climate impacts – nitrous oxide and carbon dioxide – but methane tends to dominate.
New Zealand agriculture and climate specialists Andy Reisinger and Harry Clark made a forecast of livestock’s impact on global temperatures between now and the end of this century and found cutting methane might give the planet some wriggle-room while people work to get Co2 to net zero. “If the world makes no effort to reduce carbon dioxide emissions, then livestock is hardly worth worrying about … it is an unmitigated disaster anyway,” he says. But, because of methane’s short-term potency, cows would be a significant contributor if zero-carbon policy efforts worked out well for countries. “If the world were to get really serious about reducing emissions, by 2100 you could end up with the situation where direct livestock emissions are contributing” a fifth of the warming, he says.
Paradoxically, it is when cattle are roaming, nibbling grass, that they produce most of their methane burps: up to twice as much per kilo of milk or meat as they produce eating grain. Strangely, eating grain stymies a cow’s inner methane-making microbes in a number of ways: it quickly makes an animal grow hefty, so it and its methanogens live for fewer months before becoming a burger. The animal needn’t walk far to eat, so it isn’t wasting energy. Grain also makes the rumen more acidic, which seems to make it less hospitable for the methanogens. It contains less cellulose, so hard-working microbes don’t need to break it down, meaning they create less hydrogen. And when the rumen ferments starch it seems to create more of a by-product, called propionate, which absorbs some of the hydrogen and diverts it from reaching the methanogens.
That’s not to say the overall trade-off is worth it for the cow, or the wider environment. Feedlots can cause other serious environmental issues (pollution and greenhouse gases from pooled manure, water pollution, and other things) unless they’re managed carefully. In New Zealand, it’s not clear which system would have lower overall greenhouse impacts, because feedlots require grain to be grown with chemical fertilizers, a process that itself creates greenhouse gases, and deploy fossil fuels in grain cultivation. While grass-fed beef almost certainly makes more burped methane-per-burger than the feedlot stuff, “the net balance between the two factors could go either way,” says Reisinger.
There are other effects, too. Feedlots concentrate manure and urine in one place, which can increase or decrease greenhouse gases, depending how they are managed. What mix of grainy food the cattle eat also makes a difference: feeding cows leftovers from palm oil production has higher impacts than, say, feeding them locally grown maize silage. No-one has yet thoroughly compared the total impacts of New Zealand feedlots with pasture farms, possibly because feedlots are still relatively rare here. Many people seemed shocked this month when drone footage emerged showing 16,000 cows milling in dirt paddocks near Ashburton, at a farm owned by Japanese supplier Five Star Beef.
What researchers can say, according to a study led by the University of Oxford last year is that grazing cattle have significant climate impacts that are not negated by any positive impact they have on soil health or other aspects of the environment. So much for the guilt-free burger. If you want to seriously reduce the greenhouse emissions from your diet, switching to grass-fed beef or dairy isn’t going to do it, they concluded.
Yet, while study after study shows that beef needs vastly more land, water and animal feed than pork or chicken to make each kilo of human food, and staggeringly more resources than growing most kinds of vegetable protein, appetites for beef have not shrunk enough in most developed countries to make up for soaring demand from developing countries. Rising consumption is expected to more than double worldwide demand for all meats by 2050. And, while the North American market for grass-fed beef has grown recently, it remains in the single digits. Most beef and dairy globally comes from cows munching grain out of buckets – New Zealand is an exception. Our red meat sector is well aware of it, and wants to position its grass-fed beef and lamb to survive increased scrutiny of meat by consumers, making our products ones that wealthy buyers overseas can feel good about.
But what about other countries? The Oxford-led report estimated that if all livestock were exclusively reared on grass, people worldwide could eat 7-18g of animal protein daily, rising to about 21g if cattle also ate food waste that humans cannot eat. Right now, the global forecast for 2050 is that people on average will eat about 31g of animal protein; in rich countries, people already eat more like 60g a day per person. “It would be physically impossible for the animal protein production produced today to be supplied by grazing systems, at least without an unthinkably damaging programme of forest clearance,” the authors said.
After visiting the feedlot I stop by the office of Huenerberg’s boss at Agriculture and Agri-Food Canada’s Lethbridge Research Centre, Tim McAllister, who’s been pondering these issues for years now. McAllister once spent a year living in Palmerston North, a place he claims is significantly colder than Canada’s sub-zero grasslands. He’s lived on a Canadian beef farm, and he’s seen New Zealand’s farms up close.
He says he has no problem if consumers want farmers to ditch controversial feedlot practices like the weight-boosting hormones and constant antibiotic use, or feed all cows grass all their lives. But people need to understand that farms will be less efficient at making truckloads of meat and milk. By using grain, hormone implants and antibiotics, North American farmers have inadvertently reduced their climate impact, says McAllister, by getting more meat from every cow, further assisted by selective breeding, veterinary care and improved reproductive rates. New Zealand farmers have also made large gains in the efficiency of grass-feeding, lowering their footprint for every vat of milk or kilo of meat.
Whenever McAllister thinks that the humble cow has finally reached its biological limits governing how much food it can make, scientists and farmers find a way to make each animal even more productive. He thinks cows could be made more efficient still. The question is, whether people will feel comfortable with the methods that farmers use to get there. Currently, Canada cannot export beef to Europe, where hormone dosing of cows is banned. Many Canadian and U.S. consumers are increasingly unhappy about the hormones, and routine use of antibiotics, too, fearing the rise of antibiotic-resistant super-bugs. Technologies like GM grass are on the horizon, and possibly GM cows. Dropping these methods would be fine, notes a staffer in McAllister’s office, if people dialled down their meat intake accordingly. But what is happening globally is the opposite.
Gidon Eshel, a US geophysicist at Bard College, has published studies trumpeting beef’s toll on the planet that have been widely quoted by newspapers internationally. While he’s not exactly a feedlot fan, he is a fan of shrinking the land given over to livestock farming, which leads him to favour efficiency over a farm’s outward beauty. Eshel lives in upstate New York, where he sees many small-scale pasture farms. He finds them gorgeous. But he says the idea that these bucolic farms could produce much more meat globally is, unfortunately, a “fairytale.” If people want to keep, or even grow, the world’s wild areas, he says, “we need to be getting more from every piece of farm land, not less.” To him, the obvious answer is to eat a lot less beef.
Milk comes out ahead of beef in climate assessments – it’s footprint is akin to pork, or chicken’s.
Squelching the belch
Karen Beauchemin is a highly-experienced cattle and climate scientist who works with Huenerberg and McAllister at the Lethbridge research centre. She sequesters cows in full-body chambers to see what gases comes out if she gives them a different food, or a new pharmaceutical, or other new-found treatment. She used to think solutions to cows’ climate impacts were simpler than they are. Researching the issue made her cautious.
Contrary to what some other North American researchers think, she does not think putting every cow in a feedlot is the answer. “Changing diet [from grass to grain] just to reduce methane emissions is, I believe, very dangerous,” she said when I visited her after the feedlot. “I started down this path with blinders on, looking at methane emissions — how much methane does a cow emit, how is it affected by diets and what can we do to reduce it? “And if you just keep those blinders on it’s actually not that difficult … we could just feed all our cattle grain,” she says. “But as I’ve grown into this area I start to realise that just looking at that picture in isolation … is not the story. You might end up with other problems, it might be nitrous oxide emissions because you have to use more fertilizer, or it might be a change in land use because that other crop you are recommending has lower biomass yield,” she says. “We could move them all into a feedlot … but what other environmental impacts does that have?”
Beauchemin would like to see more research done on how to make grazing cattle more efficient – the kind of research, incidentally, that New Zealanders have been working on. While New Zealand’s farms are efficient for grass-farms – with their good soil, mild temperatures, and farmers who know how to rotate cows around the paddocks to maximum young grass growth – scientists think we could get better production.
Other New Zealanders have been exploring lower-methane grass and breeding less-burpy cattle, alongside other measures. If cattle ate more digestible and nutritious grass, they would belch less methane and fatten faster; in essence, behaving a little more like grain-fed cows, says Beauchemin.
Other scientists in New Zealand and several other countries are working on methane inhibitors they could feed to cows in pill or powder form, or – the holy grail – a methane-reducing vaccine (being explored by Agresearch). So far, the Dutch are winning, because they’ve produced the most advanced methane-cutting product, a powder called 3-NOP that reduces methane belched by around 30 percent. But it’s only suitable for feedlot cows. None of these technologies, alone, will make cows carbon neutral or even close to it. But some or all of them could help.
Meanwhile, Beauchemin’s colleague, Henry Janzen, wants people to weigh up other things when they choose their meals. He designed software that tallies the greenhouse impacts of different farming methods, so he knows there’s a lot that’s not included.
A well-managed grassland farm may support biodiversity, assuming it did not rise from the ashes of destroyed Amazon rainforest. It may deliver better soil health than a feedlot, lower need for chemical fertilizers and result in cleaner waterways, depending on the farm. Or it may not, depending on the farming methods. Then there’s the philosophical side, of how people want to see cows living. “I’m really intrigued by some of the unquantifiable benefits, like driving through the countryside and seeing new-born calves gamboling about on a meadow,” says Janzen. “What’s that worth? What do you put in an Excel spreadsheet? But for many people, including many urbanites, those are big benefits.”
Janzen believes one good way to weigh up how much, and what, meat to eat, is to imagine a new currency: greenhouse gases. If someone has a unit to spend, would they prefer to see a calf gambol on a green pasture, then eat it, or eat tofu and save up their greenhouse credit for a flight to London? “Wherever you live, you derive your sustenance from the land,” he says. “And it works both ways. What happens on the land is powerfully influenced by decisions made daily in the cities and people who are deciding whether to eat beans or beef.”
One more thing. It would be nice, he says, if people also considered what the land their food is grown on is suited to: is it housing cows, growing crops to directly feed people, or a carbon-sequestering forest? After all, Beauchemin adds later, if people around Lethbridge, Alberta gave up cattle entirely, what food would the cold, arid Canadian grasslands produce? “What are we going to grow, pineapples?” she says.
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