Resumen
The beef supply chain has multiple negative impacts on the environment. A method widely used to measure impacts from both the use of resources and the emissions generated by this sector is the life cycle assessment (LCA) (ISO 14040). This study aimed to evaluate a semi-intensive system (SIS) and an extensive organic system (EOS), combined with two different slaughterhouses located in the northeast of Portugal. The studied slaughterhouses are similar in size but differ in number of slaughters and in sources of thermal energy: natural gas (Mng) vs. biomass pellets (Mp). Four categories of environmental impact were evaluated: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and photochemical ozone creation potential (POCP). As expected, higher impacts were found for SIS for all studied impact categories. Slaughterhouse activities, fertilizer production, and solid waste treatment stages showed little contribution when compared to animal production. Concerning the slaughterhouses activities, the main sources of environmental impact were the use of energy (electric and thermal) and by-products transportation.