Human urine could help build astronauts’ sleeping quarters on the moon, or supply fertiliser for farming.
Cattle, however, are a major contributor to greenhouse gases by passing methane front and back.
According to a study by a Washington State University research team, help might come from an unlikely source: the faeces of baby kangaroos.
For, in contrast to their parents, these have acetic acid-producing bacteria in their foregut.
After starting a bacteria culture developed from baby kangaroo faeces, an artificial rumen was used to simulate digestion.
The culture was just as effective as cows’ own methane-producing bacteria. Whether real cows could stop passing waste gases in future tests remains to be seen.
Also sustainable farming: animal feed from shellfish waste.