Maternal reactivity of ewes at lambing is genetically linked to their behavioral reactivity in an arena test

In sheep, the bond between the dam and her lambs is established during the first hours of a lamb s life. Genetic variability for behavioral reactivity of ewes assessed in an arena test performed 24 h after lambing has already been reported. However, there is no evidence that this reactivity represents the ewe s maternal reactivity at lambing in outdoor conditions. The objective of this study was to investigate whether or not the behavioral reactivity of ewes in the arena test is genetically related to their maternal reactivity measured at lambing. A total of 935 Romane ewes were studied. The maternal reactivity of ewes at the outdoor lambing site was recorded in response to a human approach and to the handling of the lambs. Their behavioral reactivity was also recorded 24 h post-lambing in the arena test that involved a separation from the litter and a human presence. Flight distance, aggressive reaction, time to restore contact with the litter at the lambing site and maternal behavior scores were moderately heritable (0.18 to 0.34), and vocalizations were slightly heritable (0.16). All of these behaviors were genetically correlated with the behavioral reactivity in the arena test. The highest genetic correlations (from 0.60 to 0.90) were found for maternal behavioral scores, flight distance and high-pitched bleats. In conclusion, behavioral reactivity in the arena test can be used to assess early maternal reactivity in standardized conditions. Such phenotyping could be used for genetic improvement of maternal behavior in sheep.