The results per ton of swine carcass (deadweight) exhibited a
significant contribution from feed production (a range of
17.6e99.5%) for all of the environmental impact categories and was
a bottleneck for climate change, terrestrial acidification, marine
eutrophication, biodiversity damage potential, natural land transformation,
and cumulative energy demand (Table 3). On the other
hand, the manure management system (MMS) contributed as high
as 59.7% and 78.6% of the total impact for freshwater eutrophication
and terrestrial ecotoxicity, respectively.