Reducing the Environmental Impact of Growing-Finishing Pig Production Through Daily Feed Adjustment: A Comparative Life Cycle Assessment

This study comprehensively explores the environmental implications of two feeding strategies in pig farming, focusing on three scenarios: Brazilian tables (BT-2017), NRC (NRC-2012), and AGPIC (AGPIC-2021). The comparison involves conventional phase-feeding (CON) and the daily fit model (DFM). The five-phase system provided the same diet to all pigs within a group during each proposed phase. In contrast, the DFM adjusted the diet based on the nutritional requirements of pigs, anticipating subsequent diets through daily adjustments. We employed a cradle-to-gate approach, with the functional unit defined as one barrow with an initial body weight of 20.61 ± 0.85 kg, raised to 138.94 ± 0.90 kg over a 120-day growing-finishing period. Input data were sourced from observed commercial records from pig farms in Brazil, including over 1,000,000 data points from pigs raised under standard industry conditions. We evaluated the impact of the life cycle by considering factors such as acidification, climate change, ecotoxicity, eutrophication, land use, resource use, and water use. The OpenLCA software (version 1.11.0) and the Environmental Footprint 3.0 impact assessment method were used. Our results indicate that the DFM consistently outperforms the CON strategy in terms of reducing environmental impacts. Among the three scenarios, BT-2017 results in higher environmental impact reductions compared with NRC-2012 and AGPIC-2021. This is due to the higher concentration of corn and soybean meal in diets. Notable reductions include in relation to land use-related climate change impacts (12.55%), freshwater eutrophication (6.21%), mineral and metal resource depletion (6.11%), and fossil resource use (4.88%). These findings highlight that even modest adjustments to feeding strategies can effectively reduce the environmental footprint of pig farming.