Genet. Sel. Evol. 38 (2006) 445-462
DOI: 10.1051/gse:2006014

Genetic parameters for canalisation analysis of litter size and litter weight traits at birth in mice

Juan Pablo Gutiérrez^a, Blanca Nieto^a, Pepa Piqueras^a, Noelia Ibáñez^b and Concepción Salgado<sup>a

a</sup>  Departamento de Producción Animal, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n. 28040 Madrid, Spain
^b  Ctr UdL IRTA, Area Prod Anim, Lleida, 25198 Spain

(Received 10 November 2005; accepted 24 April 2006 ; published online 6 September 2006)

Abstract - The aim of this research was to explore the genetic parameters associated with environmental variability for litter size (LS), litter weight (LW) and mean individual birth weight (IW) in mice before canalisation. The analyses were conducted on an experimental mice population designed to reduce environmental variability for LS. The analysed database included 1976 records for LW and IW and 4129 records for LS. The total number of individuals included in the analysed pedigree was 3997. Heritabilities estimated for the traits under an initial exploratory approach varied from 0.099 to 0.101 for LS, from 0.112 to 0.148 for LW and from 0.028 to 0.033 for IW. The means of the posterior distribution of the heritability under a Bayesian approach were the following: 0.10 (LS), 0.13 (LW) and 0.03 (IW). In general, the heritabilities estimated under the initial exploratory approach for the environmental variability of the analysed traits were low. Genetic correlations estimated between the trait and its variability reached values of -0.929 (LS), -0.815 (LW) and 0.969 (IW). The results presented here for the first time in mice may suggest a genetic basis for variability of the evaluated traits, thus opening the possibility to be implemented in selection schemes.

Key words: canalisation / variability / mice / litter size / litter weight

Correspondence and reprints: gutgar@vet.ucm.es

© INRA, EDP Sciences 2006