Issue |
Genet. Sel. Evol.
Volume 37, Number 4, July-August 2005
|
|
---|---|---|
Page(s) | 381 - 401 | |
DOI | https://doi.org/10.1051/gse:2005007 |
DOI: 10.1051/gse:2005007
Genetic analysis of emotional reactivity in sheep: effects of the genotypes of the lambs and of their dams
Alain Boissya, Jacques Bouixb, Pierre Orgeurc, Pascal Poindronc, Bernard Bibéb and Pierre Le Neindreaa Unité de Recherches sur les Herbivores ACS, INRA, 63122 Saint-Genès Champanelle, France
b Station d'amélioration génétique des animaux, INRA, 31326 Castanet-Tolosan, France
c Physiologie de la Reproduction et des Comportements, UMR85 INRA-CNRS-HN-University, 37380 Nouzilly, France
(Received 5 July 2004; accepted 24 March 2005)
Abstract -
A total of 1347 weaned lambs from eight genotypes were tested over five
consecutive years: Romanov (ROM) and Lacaune (LAC) pure breeds, the two F1
crossbreeds (RL and LR) and the offspring of ewes from these four genotypes
sired with Berrichon-du-Cher rams (BCF). The lambs were individually exposed
to three challenging tests involving novelty, human contact and social
isolation. Ten synthetic variables were used to express social reactivity
(i.e., active vs. passive strategy), exploratory activity and reactivity to
humans. BCF crossbreds were more active (i.e., high bleats, locomotion and
attempts to escape) than purebreds and F1. In contrast, ROM expressed more
passive responses (i.e., low bleats and vigilance postures) than LAC and BCF
crossbreds. In addition, ROM approached a motionless human less and had
longer flight distances to an approaching human than did LAC and BCF
crossbreds. When restrained, ROM, and to a lesser extent BROM and B
LR,
avoided human contact more than did LAC, RL and B
LAC. Most of these
differences were explained by direct additive genetic effects while maternal
influences or heterosis effects were rarely significant. The highest
heritability was for high bleats (
h2=0.48). Females were more active
and avoided human contact more than did males.
Key words: genetics / emotional reactivity / human contact / social isolation / sheep
Correspondence and reprints: boissy@clermont.inra.fr
© INRA, EDP Sciences 2005