This paper focuses on the burgeoning application of genetic techniques in livestock agriculture, examining how these are changing livestock breeding knowledge-practices and the representation of animal life. Conventional livestock breeding relies on visual appraisal of animals and maintaining performance records, whereas genetic and genomic techniques offer the potential to assess particular aspects of animals' genotypes. Advertising and promotional material produced by organisations involved in developing genetic techniques, and reportage and discussion of such techniques in the agricultural media, are used to examine the ways in which the production and value of living bodies in the future is being mapped out in emerging knowledge-practice networks which centre around particular visions and representations of what livestock bodies are and should do or be. The paper argues that bodies should be understood in part in terms of the wider spatial relationships in which they are entangled. A process of'circulating reference' [Latour, B., 1999. Pandora's Hope: Essays on the Reality of Science Studies. Harvard University Press, Cambridge, MA] is identified in which rounds of simplification occur in relation to the representation of the genetic qualities of livestock animals. However, these attempts to simplify produce new complexities when livestock breeders attempt to make use of genetic knowledge-practices. Identifying different modes of complexity, the paper discusses their spatiality in terms of differences between genetic abstractions from animal bodies and breeders 'multi-layered 'lay' knowledges of their livestock animals. © 2008 Elsevier Ltd. All rights reserved.