The Angus breed, originally from Britain and now one of the most valued in the premium beef market, stands at the center of these transformations. Introduced more than a century ago in the Pampa, its consolidation resulted from the articulation of management techniques, local knowledge and zootechnical interventions that learned to navigate ecological and political resistances. Based on a multisited, and multispecies ethnographic research developed between the Campanha Gaúcha and the Campos de Cima da Serra in Rio Grande do Sul, as well as the Planalto Serrano in Santa Catarina, among breeders of Angus cattle, the article describes how compositions between biotechnology and everyday cattle work have been redefining selection practices and genetic improvement. These tools do not replace the traditional lida campeira, but become entangled with it in daily routines, producing new forms of decision-making, care and control. This hybrid arrangement between laboratory and field participates in the construction of a specific type of bovine and, at the same time, reconfigures the ranching futures of Brazil.