Bpex has published two reports examining at the environmental impact of producing pigs and identifying opportunities for improvement.
The first is a Scoping Life Cycle Assessment of Pork Production, estimating the environmental impacts of pork production. The second is Pigs and the Environment, which looks at how BPEX can work to enhance the environmental sustainability of pork production.
http://www.meatinfo.co.uk/news/fullstory.php/aid/9905/Pig_industry_unveils_environmental_strategy.html