Cow dung contaminated with the drugs released 1.8 times more methane confirms new study. Scientists say the drugs boost methane production in cowpats - apparently by favoring antibiotic-resistant, methane-producing organisms in the gut.
The researchers say it’s proof that antibiotic use on farms has cascading effects on the environment. Antibiotics also change the microbes which inhabit dung beetles, although apparently with no adverse effects.
For the new paper, in Proceedings of the Royal Society B, researchers found that the antibiotics changed the microbes in the digestive system of dung beetles, which are vital for cycling carbon and improving soil. The beetles, though, did not appear to be damaged.
By contrast, clear harm was measured in the antibiotic-contaminated cowpats themselves, which produced 1.8 times more methane which is a powerful greenhouse gas.
One of the authors, Tobin Hammer from the University of Colorado, said that most methane generated by cattle is actually released as burps, and we think that antibiotics are likely to increase burped methane as well - but in this study we weren't able to measure that directly.”