Scientists Potty-Trained Cows to Help Reduce Environmental Pollution

Calves trained to urinate in an indoor latrine “showed a level of performance comparable to that of children,” according to a new study.
Calves trained to urinate in an indoor latrine “showed a level of performance comparable to that of children,” according to a new study.
A calf using a latrine. Image: Farm Animal Biology (FBN)
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You’ve heard of cow patties, but what about cow potties? 

As it turns out, toilet-trained cattle may become a real trend in agriculture, according to a team that taught calves to urinate in specified latrines. This so-called “MooLoo” training could reduce environmental pollution from cattle urine, and could even help fight climate change by curbing ammonia emissions from farms. 

The new findings “are original and reveal a hitherto unrealized opportunity to harness the cognitive capacities of animals to help resolve pressing environmental issues without compromising animal welfare,” according to a study published on Monday in Current Biology


The notion of potty-trained cows might seem like an unexpected novelty for most of us, but for Jan Langbein, an animal psychologist at the Research Institute for Farm Animal Biology who co-authored the study, the results are “not really a surprise” given the under-appreciated cognitive skills of cattle.

“As for their learning ability, previous studies have shown that cattle autonomously learn to operate various devices in the barn and move to certain places after prompting with various stimuli,” Langbein said in an email. 

“They appear to be able to learn to associate urination with a particular place, and they can develop awareness of an association between their own excretion and receiving a reward,” he continued. “From literature, we found evidence for the feasibility of latrine training in cattle from a neurophysiological and learning theory point of view.”

With that in mind, Langbein and his colleagues devised an experimental setup to see if calves could be trained to override their urge to urinate in an outdoor environment long enough to walk through an indoor alley to a special bathroom pen. 

The experiment involved a total of 16 calves, divided into two cohorts. The animals were rewarded with treats, such as molasses and crushed barley, when they urinated in the latrines and were gently splashed with water when they urinated outside, as a deterrent. 

As these exercises were repeated over the course of a few weeks, 11 out of the 16 cows caught on to the potty-training, even when the length of the alleys between the outdoor area and the latrines was increased. Ultimately, more than two thirds of the calves “showed a level of performance comparable to that of children and superior to that of very young children,” according to the study.


Cattle urine is a major source of ammonia emissions, which can cause environmental damage by contaminating soil and water around farms. Microbes in and around agricultural facilities also convert ammonia into nitrous oxide, which is a greenhouse gas that contributes to human-driven climate change.  

“Ammonia is an indirect greenhouse gas,” explained Langbein. “About 95 percent of ammonia emissions come from agriculture, and a considerable proportion comes from cattle farming, either directly from barn air or indirectly from slurry. Ammonia is responsible for a large amount of atmospheric [nitrogen] deposition which in turn leads to eutrophication of the soil and water” causing “soil acidification and direct plant damage.” 

As a result of these concerns, agricultural groups around the world have been working on methods to mitigate emissions on both local and global levels. The new study shows that potty-trained cows could be a promising part of this multi-pronged approach. To that end, Langbein and his colleagues look forward to developing automated versions of their MooLoo training program to make it more efficient and affordable.

“We are preparing a follow-up project, in which we want to realize our results, which were worked out under experimental conditions, under practical conditions,” he said. “For this purpose, the entire training procedure must be automated. Appropriate sensors should detect urination and trigger a reward output in case of urination in the latrine.”

The success of the experiment is also another reminder that cows are capable of learning and performing tasks that require both cognitive sophistication and physical restraint. Before writing these animals off as slow simpletons, consider that many of them can evidently learn to use the toilet at a much younger age than humans.