Portraits of famous cattle, sheep and horses crowded the agricultural journals on both sides of the Atlantic in the 1830s, 40s, and 50s. More than simple representations, these images were intended to shape the animals they showed-establishing standards of taste that would allow breeders to create “thrifty” meat-producing bodies, while advertising the bloodlines of already thrifty animals. In doing so, they became central to the expansion of a new form of domestic animal: the “improved breed.” In the early eighteenth century, “breeds” had been understood to emerge from particular kinds of places. Emerging in the mid-eighteenth “improved breeds” came to be defined by rules of ‘blood’ and kinship. Improved cattle were novel bodies; they grew to enormous sizes, came in new shapes and colors, and dominated the new agricultural fairs. Their blood relationships, the source of their value, were recorded not only in internationally circulated record books, but also in a linked and elaborate tradition of portraiture. This article shows how the transatlantic circulation of cattle portraits shaped both the changing definition of breed and the bodies of the animals defined. As cattle were bred to match new forms of taste, made concrete by prices in the market, portraits and cattle became more uniform. At the same time, the paper argues, ideas about the meaning of these changes diverged and fragmented. Recorded over generations by portraits, changing cattle bodies lent themselves to radically different ideas about nature, and about human and divine capacity to shape living bodies.