The New Zealand and German team of researchers had to admit it: the experiment started with a joke.
In a study published in the journal Current Biology on September 13, 2021, they claim to have successfully trained calves to use the toilet.
An unusual but useful project.
Because the management of nitrogen-rich bovine urine could in the long term have real benefits for the climate.
Cow urine: producer of greenhouse gases
"If we could collect 10 or 20 percent of the urine, that would be enough to dramatically reduce greenhouse gas emissions and nitrate leaching," said Douglas Elliffe of the University of Auckland.
According to Elliffe, the nitrogen in cow urine breaks down over time into two problematic substances: nitrous oxide, a potent greenhouse gas, and nitrate, which builds up in the soil. then seeps into rivers and streams.
Nitrous oxide accounts for around 5% of greenhouse gas emissions and just under 10% of New Zealand's emissions, according to official figures.
However, more than half of these emissions are linked to livestock.
Results comparable to those of a three-year-old
Researcher Lindsay Matthews acknowledges that the idea of training cows to use the toilet to collect and process their urine came to her when he was interviewed on the radio in 2007 and a joke was made on the subject. Together with colleagues in Germany, the scientists used food as a reward to train sixteen calves to urinate in a latrine pen. They ensure that the results are comparable to those expected for a three-year-old.
For Elliffe, the study, published this week in the journal Current Biology, "provides evidence" that it is possible to teach a cow to urinate in a toilet. “The challenge is to change the scale,” he adds. To train large herds and adapt the principle to environments like New Zealand where animals spend more time outdoors than in stables. "
Agriculture is responsible for about half of New Zealand's greenhouse gas emissions, mainly in the form of methane and nitrous oxide. Methane accounts for 43.5% of the country's emissions, almost as much as the amount of carbon dioxide generated by fossil fuels. This prevalence of methane emissions, unusual for a developed country, is explained by an economy based largely on agriculture.
