title: Responsiveness to "social" releasers in cattle. II. Relation between social status and responsiveness, and possible effect of previous familiarization with the test conditions.
abstract: The data of two previous experiments, investigating the effects of social releasers in Friesian-Dutch heifers were analysed in order to verify whether the frequency of approach responses to models and calls of conspecifics was modified by pre-experimental factors. First, responsiveness was correlated to the social status of individuals; a social hierarchy was assessed on the basis of agonistic interactions recorded for a 2-month period prior to the experiments with models. A significant positive correlation was found between the total number of responses and the total number of escape-avoidance reactions to aggressive acts. The same result was found when individual ranks were assessed on a hierarchy re-presenting a dominance order established on the basis of the number of aggressive acts causing escape-avoidance reactions. In this case, also, animals with highest ranks presented a significantly higher number of responses to models than animals with lowest ranks. In our second experiment, a significant positive correlation was found between all criteria used to assess individual ranks in a hierarchy, while this result was not found necessarily in the first experiment. The other pre-experimental factor under consideration was a possible familiarization with the testing conditions (models/calls of conspecifics, handling, and other procedures); some of the group-members tested during the second experiment had already been tested in the first one, carried out a year before. Many results demonstrated that the frequency of responses to social releasers was significantly lower for the previously tested subjects than for the animals tested for the first time.
authors.affiliation: Centre de Psychologie Expérimentale et Comparée de l'Université de Louvain, 3041 Pellenberg Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Soffié
authors.forename: R
authors.initials: R
authors.lastname: Zayan