A survey on environmental footprint of intensive beef herds based on farm data: gate-to-gate LCA approach

Livestock has been recognized as an important contributor to environmental impact of human activity. The beef sector of Veneto Region (Italy) represents a main player in the national beef production, but knowledge on its overall impact lacks. This study aimed to survey the environmental footprint of intensive beef sector in Veneto Region through a gate-to-gate Life Cycle Assessment (LCA) approach. The study considered 1 kg of body weight (BW) as functional unit and the batch (a group of animals homogenous for breed, diet, fattening period, and finishing herd) as system boundary. Greenhouse gas (GHG) emission (kgCO2-eq), acidification (gSO2-eq) and eutrophication (gPO4-eq) were taken as impact categories. The study involved 328 batches and 16 specialized beef fattening herds. Information about breed (mainly Charolaise, Limousine and French and Irish crosses), sex, fattening period (226±17 d), initial and final BW (365±47, 686±82 kg, respectively), composition of Total Mixed Ration (TMR), dry matter intake (10.2±1.2 kg DM/d) and growth rate (1.43±0.20 kg/d) were recorded or computed for each batch. Data on materials used (plastic, fuel, electricity), and dedicated-to-feed-herd crop production were collected for the year 2013 in each herd. Off-farm emissions have been acquired from literature data and software (Simapro 7.3.3 – Ecoinvent database v.2.2). Different methods were used to assess the impact categories resulting in a range of possible values. The impact on GHG emissions category ranged from 7.3±1.2 to 8.7±1.4 kg CO2eq/kg BW, on acidification was 206±52 g SO2eq/kg BW, while on eutrophication 41.2±10.5 g PO4eq/kg BW. Impact categories were analysed according to a mixed model with breed, arrival season and BW, neutral detergent fibre (NDF), and average daily gain (ADG) classes (calculated as mean±0.5 SD within each breed) as fixed effects and herd as random effect. Breed, ADG and NDF classes influenced (P<0.01) all impact categories, while arrival season influenced only GHG emission and eutrophication categories. The environmental footprint of this specialized system seems lower than values reported for other beef fattening systems. However, high variation was observed among estimates obtained using different methods, suggesting the need to standardize the approaches used for LCA analysis. Moreover, further research is needed to extend the system boundary for including the production of stock calves in the country of origin.