Biogas potential from U.S. livestock farms

Other countries have developed large-scale production of biogas and electricity from livestock manure. With the proper regulatory environmnet and incentives, the U.S. could do the same. This article and the comments are a good introduction to the benefits and challenges of biogas from livestock manure.
Biogas: what options for Slurry power in the US? - Renewable Energy World: "Intensive animal farming produces large amounts of waste – about 75 kg per cow, per day – that is both a source of methane pollution and a potential groundwater pollutant. Using anaerobic digestion to treat animal slurry can provide a solution to this problem, as well as renewable energy."