Environmental impact of heavy pig production in a sample of Italian farms. A cradle to farm-gate analysis

Four breeding piggeries and eight growing-fattening piggeries were analyzed to estimate potential environmental impacts of heavy pig production (> 160 kg of live height at slaughtering). Life Cycle Assessment methodology was adopted in the study, considering a system from breeding phase to growing fattening phase. Environmental impacts of breeding phase and growing-fattening phase were accounted separately and then combined to obtain the impacts of heavy pig production. The functional unit was 1 kg of live weight gain. Impact categories investigated were global warming (GW), acidification (AC), eutrophication (EU), abiotic depletion (AD), and photochemical ozone formation (PO). The total environmental impact of 1 kg of live weight gain was 3.3 kg CO₂eq, 4.9 E − 2 kg SO₂eq, 3.1 E − 2 kg PO₄³⁻ eq, 3.7 E − 3 kg Sbeq, 1.7 E − 3 kg C₂H₄eq for GW, AC, EU, AD, and PO respectively. Feed production was the main hotspot in all impact categories. Greenhouse gases responsible for GW were mainly CH₄, N₂O, and CO₂. Ammonia was the most important source of AC, sharing about 90%. Nitrate and NH₃ were the main emissions responsible for EU, whereas P and NOx showed minor contributions. Crude oil and natural gas consumption was the main source of AD. A large spectrum of pollutants had a significant impact on PO: they comprised CH₄ from manure fermentation, CO₂ caused by fossil fuel combustion in agricultural operations and industrial processes, ethane and propene emitted during oil extraction and refining, and hexane used in soybean oil extraction. The farm characteristics that best explained the results were fundamentally connected with performance indicators Farms showed a wide variability of results, meaning that there was wide margin for improving the environmental performance of either breeding or growing-fattening farms. The effectiveness of some mitigation measures was evaluated and the results that could be obtained by their introduction have been presented. - Highlights: • Pig production has relevant effects on water and air quality, global warming and natural resource depletion. • An LCA was performed on the production of heavy pig (> 160 kg of body weight) production. • There is a wide variability of environmental performances among farms. • It is shown that there is wide margin of reduction of environmental impact of heavy pig production.