title: How do pigs behave before starting an aggressive interaction? Identification of typical body positions in the early stage of aggression using video labelling techniques.
abstract: The aim of this study was to identify, quantify, and describe pre-signs of aggression in pigs and the early stages of aggressive interactions. The experiment was carried out at a commercial farm on a group of 11 male pigs weighing on average 23 kg and kept in a pen of4 m x 2.5 m. In total 8 hours were videorecorded during the first 3 days after mixing. As a result, 177 aggressive interactions were identified and labelled to find pre-sign body positions before aggressive interactions, attack positions and aggressive acts performed from these positions. A total of 12 positions were classified as pre-signs (P1-P12) and 7 of them were identified immediately at the start of aggressive interactions (P6-P12). Most common pre-sign positions were P3-pigs approaching and facing each other (24%) and P2-initiator pigs approaching from the lateral side (18%). In 80% of the cases the duration of pre-signs was 1-2 sec 72% of all aggressive interactions were short (1 to 10 sec). The most frequent attack positions were P12-inverse parallel (39.5%), P7-nose to nose, 90 degrees (19.77%) and P9-nose to head (13.5%). The most frequent aggressive acts from attack positions were head knocking (34.4%), pressing (34.4%) and biting of different body parts (29.4%). Head knocking was mostly observed in relation to P7 and P2 positions and biting was common in the P7 position. In conclusion, pigs adopt specific pre-signs and body positions before the escalation of aggressive interactions. This could be used as potential sign to identify a beginning aggression.
authors.affiliation: Department of Veterinary and Technological Sciences for Food Safety, Faculty of Veterinary Medicine, Università degli Studi, Milan, Italy. gunel.ismayilova@unimi.it
authors.forename: Gunel
authors.initials: G
authors.lastname: Ismayilova
authors.forename: Maciej
authors.initials: M
authors.lastname: Oczak
authors.forename: Annamaria
authors.initials: A
authors.lastname: Costa
authors.forename: Lilia Thays
authors.initials: LT
authors.lastname: Sonoda
authors.forename: Stefano
authors.initials: S
authors.lastname: Viazzi
authors.forename: Michaela
authors.initials: M
authors.lastname: Fels
authors.forename: Erik
authors.initials: E
authors.lastname: Vranken
authors.forename: Jörg
authors.initials: J
authors.lastname: Hartung
authors.forename: Claudia
authors.initials: C
authors.lastname: Bahr
authors.forename: Daniel
authors.initials: D
authors.lastname: Berckmans
authors.forename: Marcella
authors.initials: M
authors.lastname: Guarino
mesh_terms: D000374:Aggression / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D011187:Posture / Q000502:physiology*; D034421:Sus scrofa / Q000502:physiology*; D013552:Swine; D014741:Video Recording / Q000379:methods*