Researchers Potty Trained Young Cows, a Promising Measure to Reduce Greenhouse Gases

One cow pees up to eight gallons a day; training them is easy, and capturing and treating the waste could make a difference

Cow urinating in a pen
Enticed by a sweet treat, a cow learns to use the "MooLoo," a latrine for cattle, where excrement can be collected. The only question is: can this technique work on a larger scale?

It’s easier to potty train calves than children. Who knew?

Scientists knew, it turns out. They discovered this while looking for a way to reduce the amount of greenhouse gases produced on farms. By teaching young cows to use the “MooLoo”—a latrine for cattle—the excrement can then be collected and reused for fertilizer while controlling the harmful impact of nitrous oxide in the environment.

Surprisingly, the calves took to the training rather easily and quickly, according to Lindsay Matthews, an animal behavioral scientist at the University of Auckland and one of the authors of a study published in the peer-reviewed journal 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,” he tells David Grimm of Science magazine. Matthews adds that it took only 15 days to train the calves. Children, typically, take much longer to potty train.

Cattle pee a lot—up to eight gallons a day per cow. That urine contains nitrogen, which turns into ammonia when mixed with feces—an all-too-common problem in the barnyard, reports Hannah Devlin of the Guardian. So researchers wanted to see if they somehow could capture urine from cows to reduce agricultural pollution.

Researchers Potty Trained Young Cows, a Promising Measure to Reduce Greenhouse Gases
The idea of training calves to urinate in a designated pen, says researcher Lindsay Matthews (above), originally came to him when he was speaking with a radio host in 2007. Research Institute for Farm Animal Biology

Microbes in the soil convert ammonia into nitrous oxide, which comprises seven percent of all greenhouse gasses in the United States, according to the Environmental Protection Agency.

Cattle farms are responsible for half of the ammonia produced in Europe, says study co-author Jan Langbein, an applied ethologist at the Research Institute for Farm Animal Biology (FBN) in Germany. Studies show that capturing 80 percent of cow urine worldwide would lead to a 56 percent reduction in ammonia emissions, says the Guardian.

“Voiding in a specific location (latrine) would help resolve this dilemma by allowing ready capture and treatment of excreta under more spacious farming conditions,” the scientists state in the study.

Training the calves to urinate in one place began in jest. In 2007, a radio interviewer joked with Matthews about potty training young cows in order to control ammonia emissions, reports Seth Borenstein of the Associated Press (AP). The idea resonated with the scientist, who started an experiment in 2009, but then funding ran out.

A couple of years ago, Matthews and Langbein teamed up with other colleagues to try it again. The team taught 16 Holstein calves to use an enclosed area designed to capture their excrement by rewarding successful urination with a molasses mixture or crushed barley.

The experiments were conducted in an indoor facility at FBN. Using diuretics to get the calves to pee, scientists allowed the test subjects to roam about until they felt the urge. When they had to go, 11 pushed into the pen, did their duty and received their reward, reports AP.

The next step is to learn how to use the practice for larger herds and convincing farmers of the necessity of doing so. If they buy into potty training cattle, the MooLoo could make it significantly easier to control waste products and reduce greenhouse emissions.

“I am not surprised they can train calves to urinate in set locations, but I am surprised no one has demonstrated this before,” Brian Hare, a Duke University animal cognition scientist who wasn’t part of the research, tells AP. “The critical question is can it and will it scale?”