"Temperament in farm animals, such as sheep, cattle and quail, has a strong genetic basis. In sheep, the temperament of young lambs born from a calm or nervous mother is not affected by the genotype of the rearing mother as demonstrated with a cross-fostering experiment (Bickell et al., 2009b). Briefly, the temperament of the cross fostered progeny was assessed at two occasions, one week after birth by measuring locomotor activity during an open-field test and at weaning (16 weeks) by measuring locomotor activity during an arena test and agitation score measured during an isolation box test. At both time points, there was a genotype effect but no maternal or fostering effect on the lamb's behaviour suggesting that temperament in Merino sheep is mainly determined by the genetic transmission of the trait rather than behaviours learned from the mother." (Dominique Blache; Samantha L. Bickell, July 2010)