Résumé : Purpose: This work aims to facilitate the territorial LCA applications through a case study on land use for livestock production in Wallonia (South region in Belgium), emphasizing the role of GIS and constructing inventory mainly with open-access data at the subnational level. Methods: We first established a coherent fodder-livestock interaction (e.g., how much grassland was used for cattle) according to feed requirement and local production. Then we collected data mainly from public data sources to estimate the inventory for a unit head of each animal category and unit area of each fodder crop type at the subnational level. Using the fodder-livestock interaction and collected data, we calculated the territorial emission factors for animal land use, which aggregates the life cycle emissions from unit area of land use containing fodder crops and livestock that these fodder crops feed. We also distinguished the in- and off-territory impacts. Results and discussion: By comparing with local confidential data and life cycle inventory databases, the results calculated with open-access data show a certain level of consistency. Therefore, these open-access data are proved to help conduct the initial territorial assessment to identify the hotspots of farming practices at the subnational level even in the absence of complete information. In addition, by applying the territorial emission factors for animal land use, the case study emphasizes the role of the geographic information system in the territorial LCA. Conclusions: This work contributes to operationalizing the territorial LCA study on the animal-related territory, facilitating the development of more uniform methods to establish life cycle inventory across different countries in Europe for the agricultural sector. We also pointed out the potentials for future work.