Development of international genetic evaluations of dairy cattle for sustainable breeding programs

Abstract

SummaryA large proportion of dairy foods consumed by humans are produced using milk from commercial dairy breeds. The result of high selection intensities, narrow breeding objectives and ignoring inbreeding in past decades is that much attention now needs to be given to conserving these commercial breeds to maintain and increase food production and meet future demands. The characteristics of a sustainable breeding program are broad breeding objectives, measures to control inbreeding rates and continuous genetic improvement to keep populations competitive. It is necessary to include traits in the breeding objectives that reduce the cost price of products in addition to traits that increase the output of products. Breeding objectives differ between countries (production environments), and together with genotype-environment interaction for single traits (e.g. milk yield) the implication is that ranking of animals for local breeding goals differs between countries (production environments). Acknowledging this in selection programs leads to larger number of selected animals - at least on a global level, adding to the global diversity in commercial dairy cattle populations. Interbull provides international comparisons of bulls from six dairy breeds for most of the economically important traits, thereby enabling global selection for broad breeding objectives in many countries around the world.