Assessing walking posture with geometric morphometrics: effects of rearing environment in pigs
2016
Tallet, Céline | Sénèque, Emilie | Mégnin, Claire | Morisset, Stéphane | Val-Laillet, David | Meunier-Salaün, Marie-Christine | Fureix, Carole | Hausberger, Martine | Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage [Rennes] (PEGASE) ; Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST | Ethologie animale et humaine (EthoS) ; Université de Caen Normandie (UNICAEN) ; Normandie Université (NU)-Normandie Université (NU)-Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS) | Société Ingénierie, études techniques | Nutrition, Métabolismes et Cancer (NuMeCan) ; Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM) | This project was partially funded by a grant from Rennes 1 University (Projets émergents) and was made possible thanks to scientific meetings of the GIS CCS (Groupement d’Intérêt Scientifique, Cerveau-Comportement-Société). The authors are grateful to Patrice Roger, Jérémy Rissel, Vincent Piedvache, Fabien Guérin, Kardiatou Sy, Carole Guérin, Michel Lefèbvre and Sylvie Guérin for their participation in different phases of the experiment. We thank the ISAE and Mike Appleby, who kindly edited for readability and for correct English in the revised manuscript.
International audience
显示更多 [+] 显示较少 [-]英语. Rearing social animals like pigs in isolation from conspecifics can have consequences on behaviour and physiology. The aim of this experiment was to determine whether rearing conditions affect body postures. We adapted a method for quantitative evaluation of postures based on geometric morphometrics, developed in horses, for pigs and applied it in different conditions. Forty eight 75-day old females were reared either alone in 2.25 m2 pens (IH, N = 24 animals and 4 groups) or in groups of four in 4.64 m2 pens (GH, N = 24) for two weeks. They were habituated to human handling (stroking, speaking) and marking on their backs every day, and tested individually once a day for 10 min in a corridor outside the home pen during the two subsequent weeks. We observed their behaviour and posture during the first exposure to the test (novelty), and the fourth and fifth (after habituation). On the sixth and seventh tests, a familiar stockperson was present in the corridor (human presence). Before each test, the animals were marked with seven landmarks along their length, corresponding to anatomical points and easily located. An experimenter took pictures of the animals walking along the corridor, and these pictures were transferred to tps software for analysis. GH animals were more often active in the rearing pen than IH (median (IQ) 15% of observations [12-20%] versus 2% [0-13%]; P < 0.05). All animals except one IH initiated contact with the handler during the last sessions of handling (Fisher's exact test, ns). Principal Component Analyses revealed significant effects of rearing and testing conditions on pigs’ behaviour and posture. Novelty led to fewer vocalisations and more exploration for IH than GH animals (P < 0.05), but there were no differences between treatments after habituation to the testing situation. The backs of IH animals were more rounded than those of GH (P < 0.05; dimension 1 of PCA), independently of the test condition. Human presence had no effect on posture. In conclusion, the method based on geometric morphometrics that we developed to study pig posture detected variations in walking posture in pigs associated with rearing conditions. Postures might reflect affective states in pigs, as shown in other species, but further studies are needed to verify this
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