How do feed lots use manure?

I was not previously aware that the Genesis ethanol plant in Mead, Nebraska has been using the methane from cow manure to distill ethanol, and in turn, feeding the leftover corn mush to the cows. ("Nebraska Ethanol Plants Will Run Without Fossil Fuels"). The use of methane actually allows the plant to run without using fossil fuels and the people at E3 Biofuels claim that is process is highly environmentally friendly because it keeps methane, a greenhouse gas, out of the atmosphere. However, when methane is burned as a fuel, it produces carbon dioxide, another greenhouse gas. I was shocked by that fact, so I dug a little further.

It turns out that, although carbon dioxide has given greenhouse gasses a bad name, "methane is over 20 times more effective at trapping heat in the atmosphere than carbon dioxide" according to the U.S. Environmental Protection Agency. The symbiotic relationship between the Genesis ethanol plant and its attached feed lot isn't necessarily great for the environment, but it does reduce the impact of one feed lot.

While this new discovery of mine does not really redeem feed lots in my mind, I am growing more certain that feed lots are always going to be part of Nebraska's economy. Feed lots that serve a dual purpose like the one attached to the Genesis ethanol plant will come closer to maximizing their usefulness, but they will always smell like manure.