When we talk about greenhouse gas emissions from livestock, methane from cows tends to dominate the discussion. But other waste, notably feces and urine, are also produced in staggering amounts, and can have their own damaging effects on the environment. Scientists, responding to what seems to have been a joke on a New Zealand radio show, according to the Associated Press, have actually figured out how to potty-train cows, at least to an extent.
Methane, the most dominant greenhouse gas emitted by ruminants like cows, comes mostly from belches. But cow urine is also a big deal. According to some studies, ruminants like cows “are poor nitrogen converters,” meaning that between 70 and 95 percent of the nitrogen they take in through their diet is deposited in their waste. Exactly how much damage the nitrogen in cow urine is doing to the environment is a broad question that doesn’t have a clear answer. It seems to vary dramatically based on breed, location, diet, soil makeup, temperature, the presence of certain plant species, and many more variables. Plus, the emissions calculations often combine solid and liquid waste, which may interact with each other but are not always present in the same place.
That all said, it is pretty well known that the nitrogen in cow urine can react with manure to form ammonia (bad), or react with soil microorganisms to create nitrous oxide (also bad) and contaminate soil through mass excretions which create “cow urine patches” (this too is bad). Nitrous oxide is an extremely efficient, dangerous greenhouse gas and agriculture is responsible for around three-quarters of the United States’s emissions each year.
The researchers involved in the study attempted something relatively simple: to potty-train cows. They did this with a classic reward system, where cows that urinated in an assigned area were rewarded with a sweet treat and those who urinated outside the area got a spritz of cold water. Within 15 days, the cows were fully capable of using the toilet area, though it’s worth noting that the cows were given diuretics that prompted them to pee more often, in order to condense the experiment.
The idea of potty-training cows, though, has limitations. There’s been no work on potty-training for feces, though that seems possible enough. The bigger issue is space and treatment. Pasture-grazing cattle don’t have access to a toilet and are sometimes in such large herds that dozens of separate toilets would be needed. Dairy cows, though they’re indoors, don’t move around very much. Many dairy cows are restricted to one small area, rather than allowed to freely go to the bathroom as needed. Basically, it’s hard to imagine many current livestock systems that could incorporate toilets for cows.