Behavioural reactivity, social and cognitive abilities of Vietnamese and Pitman–Moore weaned piglets
Résumé
Miniature pigs are increasingly used as alternative models in biomedical research, but little is known about their behavioural reactivity. However this should be taken into account when selecting breeds. In the present study, behavioural reactivity, social and cognitive abilities of 63 weaned piglets from the Pitman–Moore (16 females and 17 males) and Vietnamese (15 females and 15 males) miniature breeds were assessed in three test situations. They were first isolated in an open-field test and confronted with an unknown human. They were then confronted to the presence of familiar and unfamiliar piglets in a T-maze test. Finally, their reaction to the reunion with and separation from a littermate was assessed in a Y-maze test. Overall, Pitman–Moore piglets systematically expressed more locomotion, vocalisations and exploratory behaviour than Vietnamese piglets (principal component analysis; P < 0.0001). They were also more prone to initiate contact with an unknown human during an open-field test (P < 0.05), but less easy to catch in their home pen (P = 0.001). Piglets from both breeds spent 80% of their time close to either the familiar or the unknown piglet in a T-maze, male piglets preferring the unknown conspecifics (P < 0.05). While piglets of both sexes spent 75% of their time near their littermate rather than an empty pen in a Y-maze test, only females spent more time near the area that was previously associated with the presence of this littermate (P = 0.012), suggesting the acquisition of short-term social-conditioned place preference. In sum, these results provide a novel insight into the behavioural traits that characterise the temperament of the Pitman–Moore and Vietnamese minipig breeds, and open the way to further attempt at investigating their ontogenetic roots as well as selecting specific traits for better use of these breeds in research.