Genet. Sel. Evol. 36 (2004) 373-394
DOI: 10.1051/gse:2004007

A method for the dynamic management of genetic variability in dairy cattle

Jean-Jacques Colleau^a, Sophie Moureaux^{a, b}, Michèle Briend^a and Jérôme Bechu<sup>c

a</sup>  Station de génétique quantitative et appliquée, Institut national de la recherche agronomique, 78352 Jouy-en-Josas Cedex, France
^b  Institut de l'élevage, 75595 Paris Cedex 12, France
^c  Génétique Normande Avenir, 61700 Domfront, France

(Received 18 August 2003; accepted 1 March 2004)

Abstract
According to the general approach developed in this paper, dynamic management of genetic variability in selected populations of dairy cattle is carried out for three simultaneous purposes: procreation of young bulls to be further progeny-tested, use of service bulls already selected and approval of recently progeny-tested bulls for use. At each step, the objective is to minimize the average pairwise relationship coefficient in the future population born from programmed matings and the existing population. As a common constraint, the average estimated breeding value of the new population, for a selection goal including many important traits, is set to a desired value. For the procreation of young bulls, breeding costs are additionally constrained. Optimization is fully analytical and directly considers matings. Corresponding algorithms are presented in detail. The efficiency of these procedures was tested on the current Norman population. Comparisons between optimized and real matings, clearly showed that optimization would have saved substantial genetic variability without reducing short-term genetic gains.

Key words: relationship coefficient / mating / optimization / breeding scheme

Correspondence and reprints: ugencjj@dga2.jouy.inra.fr

© INRA, EDP Sciences 2004