Interbull: Constructing International Commensurability for Dairy Cattle Selection

Abstract

Since the middle of the XXth century, the most productive Holstein breed has become the main product exchanged on the international market of breeding animals. The propagation of new technologies of genetic evaluations and breeding has been led by commercial needs marked by complementary logics of importing and exporting countries. This socio-historical analysis argues that the crucial issue for the international trade balance is the commensuration (or the process of making things comparable through a common metric) of national standards of genetic evaluation of marketed sires. Indeed, the product quality is constructed by its comparison and ranking with categories of similar products. While the true product quality is unknown or uncertain in genetics, the commensuration, as both a technical and a social process becomes paramount. The Interbull initiative has been driven from 1970’s until now by research of a mean to objectively compare bull breeding values and motivated by the will of European importers to efficiently buy exotic (North-American) Holstein bulls and semen. The long scientific and political negotiations around the biological problem of accounting for “genotype by environment interaction” which was identified as a crucial point for the commensurability of genetic values resulted in the technical solution of the MACE model. A transnational space of commensurability has been formed within the technical infrastructure of Interbull Centre, providing comparable genetic evaluations of bulls, with MACE as a service to countries concerned by international trade of genetic material. Mechanisms of inclusion and exclusion of this technical space of commensurability have shaped those of the international genetic trade. The new technology of genomic evaluations and the market liberalization in the 2000’s have destabilized the international commensuration. With a broadened and diversified community of players and with a new issue of genotype data sharing put in the center of technical and political negotiations the genomic selection showed the limits of the existing commensurability. Within this changing context the main challenge remains however the same: find out a new technical mean to take in account the key-point of the international commensurability of genetic values: biological aspect of “genotype by environment interaction”. Thus, the Interbull case can help to understand mechanisms of international circulation of technologies for genetic and genomic evaluation through considering of the commensuration as a dynamic process rather than a static finality to come to. This process allows keeping the diversity of standards, to adapt and to re-adapt technical tools to the changing political, biological and technological issues.