Data under siege : Making cattle flows (il)legible in the Brazilian Amazon

In recent years, intense fires in the Amazon have put the spotlight on the deep intertwining between Brazil's beef industry and rainforest destruction. As increasing evidence suggested that cattle raised in illegally cleared lands routinely fed the slaughterhouses owned by major meatpacking companies (JBS, Marfrig, Minerva), these have faced unprecedented criticism. In this context, an already-existing data infrastructure known as the GTA (‘Gûia de Transito Animal’) has become a bone of contention. Developed since the late 1990s by Brazilian veterinary authorities, the GTA keeps track of all cattle movements occurring within national borders : although it was initially designed to allow a rapid reconstruction of contagion chains in case of epizootic disease – a function that it still fulfils –, from 2018 onwards civil society actors started to use it as a proxy to detect deforestation and illegal cattle farming in the supply chain of slaughterhouses. This sudden, unexpected enlargement of the GTA's scope – i.e., from animal health to environmental traceability – quickly sparked tensions, with big meatpackers, farmers unions, journalists, environmental NGOs, scientists and state administrations defending contradictory agendas. In this article, I aim to reconstruct the socio-historical trajectory of this controversy, and to map out the manifold consequences of this twisted use of animal transit data. Exploring the ecologies of the GTA (the way it is designed, produced, maintenanced, circulated) will allow to show how digital technologies can become loci of intense power struggles in a time of environmental devastation.