Not in the future, according to this from BusinessGreen, as manure can readily be turned in methane using anaerobic digestors, which can then be burned to create electricity, or converted into a feed-stock for biofuels.
"Anaerobic digestors work like small-scale landfill sites, trapping methane from waste organic matter, such as slurry, manure and food waste, that can then be burnt off to produce heat and electricity or converted into biofuel, while also producing a nutrient rich digestate that can be used as a fertiliser."
"This material could produce enough heat and power to run more than two million homes, helping to prevent dangerous climate change by providing a renewable energy source as well as reducing our reliance on landfill."
So there you have it - even cow manure could become a renewable energy source!