How does a prankster get on phone line with a cabinet secretary?
Some staffer didn't do his due diligence. The subject is not inherently implausible. Conversion of animal waste (plant waste too, for that matter) to fuel was going gangbusters a few years ago. I don't follow it closely but I suppose fracking and very cheap natural gas may have undercut the economics, but in principle it's a good thing to do. The energy supply issues aside, it's a great waste management strategy for large scale feedlot operators, provided the numbers pencil out.
Large feedlots produce far more manure than they can sell to organic farmers looking for "natural" fertilizers. (Why so many soccer moms who get their information from Facebook prefer food grown in poop is beyond me.) Alternatively, we could weaponize the pig poop and spray it across ISIS occupied regions as a disinfectant. This should be explored.