“Why not just potty train the cows?” That’s what a radio jockey asked animal behaviorist Lindsay Matthews during a 2007 interview about how cow urine harms the environment. The question was in jest, but it got Matthews—a researcher at the University of Auckland—thinking. Now, nearly 14 years later, he and colleagues have accomplished what many thought impossible: They’ve taught nearly a dozen calves, which normally pee and poop at random, to “hold it” and urinate in a specific location. Yes, dear readers, the bovines learned to use the bathroom.
The new finding is far from a parlor—or pasture—trick. If applied to the 270 million dairy cows across the globe, it could put a serious dent in the toxic chemicals and greenhouse gases produced by bovine waste.
“It’s a huge issue,” says Lindsay Whistance, an applied ethologist at the Organic Research Centre, a U.K.-based organization that works to make farms more environmentally friendly. She also likes that scientists are taking the bovine mind seriously. “These animals are capable of much more than we ask of them.”
Whistance tried her hand at potty training cows in 2009. Looking for ways to keep the animals from soiling their bedding, she and colleagues taught a handful of calves to relieve themselves for a reward. Right after they peed or pooped, the cows turned to Whistance for a treat, showing they were aware of their bathroom habits. But funding for the project ran out, and Whistance wasn’t convinced that toilet training cows would be practical for farmers or the cattle themselves.
That’s where Matthews came in. A few years after his radio interview, he was chatting with colleagues about a problem he coined the “climate killer conundrum.” Since the early 2000s, farmers in Europe and other regions had moved from chaining dairy cows in a barn or confining them in small stalls to giving them more room to roam indoors. But now, instead of the urine and feces from dozens of animals going straight into an easy-to-clean trench, it slopped all over the concrete floors.
Scattered excrement can cause bacterial infections in cows. And when their poop mixes with pee, it creates an environmental hazard: ammonia, which can transform into the potent greenhouse gas nitrous oxide. Half of the ammonia produced in Europe comes from cattle farms, says study co-author Jan Langbein, an applied ethologist at the Leibniz Institute for Farm Animal Biology. Given the hundreds of millions of dairy cows in the world, he says, studies have shown that capturing 80% of cow urine would lead to a 56% reduction in ammonia emissions.
So Langbein and his Leibniz colleagues constructed a small barn on the grounds of their institute. The inside looked like a queue for an amusement park ride. Metal pipes and railings formed long hallways that ended at a swing-open gate, which stood in front of a square patch of artificial turf—the cow commode. (The team calls it the “MooLoo.”) Inside, a window could open to provide the animals a treat—a molasses mixture or crushed barley.
In phase one of the potty training, the team gave 16 Holstein calves a diuretic before confining each one to the MooLoo. The animals were rewarded with food whenever they urinated. After 10 to 30 tries, 10 calves learned to associate peeing with the treat: They turned to the food window right after urinating (see video, above)—sometimes midstream. “They learned really quickly,” Langbein says.
In the next two phases, the researchers moved the calves into the hallway, gradually increasing the distance to the latrine up to 5 meters. Cows that urinated before they got to the commode were softly sprayed with water. After five to 15 rounds in the new setup, 10 of the calves walked all the way to the bathroom to relieve themselves, almost always without an accident along the way, the researchers report today in Current Biology.
“The calves’ rate of learning is within the range seen with 2- to 4-year-old children, and faster than for many children,” Matthews says. The waste, Langbein adds, could be moved to a storage tank, used for fertilizer, or even sampled to monitor the health of individual cows.
Jeffrey Rushen, an animal behaviorist at the University of British Columbia, Vancouver, whose own team separately taught cows to urinate in a specific location—essentially phase one of the current study—calls the new work “the essential next step.” But as farmers are likely to balk at potty training hundreds of cows, researchers will need to find a way to automate the process, he says, perhaps with moisture sensors and automated treat dispensers. They’ll also need to expand the training to pooping.
“We’ve never really exploited the cognitive abilities of cows,” says Rushen, who has previously shown that the animals learn to recognize different people much faster than pigs do. “If we can use their ability to help keep barns clean, it’s not just good for the environment, it reduces the workload of the farmers.”
Still, Whistance isn’t convinced that potty training cows in the real world is realistic. The animals would have to hold their bladders for much longer distances in an actual barn and might have to muscle past dozens of other cows to get to the bathroom. “They already have to learn where to lie down and where to eat,” she says. “Now we’re telling them, ‘You can’t even have a wee when you want one.’”
If nothing else, Langbein hopes the work will burnish the reputation of the much-maligned bovine. “People think of farm animals as dirty and stupid—and that affects how we treat them,” he says. “When people realize that these animals are much smarter than we’ve given them credit for, maybe they’ll care more about their welfare.”
science.org, 13 September 2021