title: Prediction of reduction in aggressive behaviour of growing pigs using skin lesion traits as selection criteria.
abstract: Aggression at regrouping is a common issue in pig farming. Skin lesions are genetically and phenotypically correlated with aggression and have been shown to have a significant heritable component. This study predicts the magnitude of reduction in complex aggressive behavioural traits when using lesion numbers on different body regions at two different time points as selection criteria, to identify the optimum skin lesion trait for selection purposes. In total, 1146 pigs were mixed into new social groups, and skin lesions were counted 24 h (SL24h) and 3 weeks (SL3wk) post-mixing, on the anterior, centre and posterior regions of the body. An animal model was used to estimate genetic parameters for skin lesion traits and 14 aggressive behavioural traits. Estimated breeding values (EBVs) and phenotypic values were scaled and standardised to allow direct comparison across multiple traits. Individuals with SL24h and SL3wk EBVs in the least aggressive 10% of the population were compared with the population mean to predict the expected genetic and phenotypic response in aggressive behaviour to selection. At mixing, selection for low anterior lesions was predicted to affect substantially more behavioural traits of aggressiveness than lesions obtained on other body parts, with EBVs between -0.21 and -1.17 SD below the population mean. Individuals with low central SL24h EBVs also had low EBVs for aggressive traits (-0.33 to -0.55). Individuals with high SL3wk EBVs had low EBVs for aggression at mixing (between -0.24 and -0.53 SD below the population mean), although this was predicted to affect fewer traits than selection against SL24h. These results suggest that selection against anterior SL24h would result in the greatest genetic and phenotypic reduction in aggressive behaviour recorded at mixing. Selection for increased SL3wk was predicted to reduce aggression at mixing; however, current understanding about aggressive behaviour under stable social conditions is insufficient to recommend using this trait for selection purposes.
authors: 1Animal and Veterinary Sciences Group,Scotland's Rural College,West Mains Road,Edinburgh EH9 3JG,Scotland.
authors: S
authors: S
authors: Desire
authors: 1Animal and Veterinary Sciences Group,Scotland's Rural College,West Mains Road,Edinburgh EH9 3JG,Scotland.
authors: S P
authors: SP
authors: Turner
authors: 1Animal and Veterinary Sciences Group,Scotland's Rural College,West Mains Road,Edinburgh EH9 3JG,Scotland.
authors: R B
authors: RB
authors: D'Eath
authors: 2Division of Genetics and Genomics,The Roslin Institute,University of Edinburgh,Easter Bush,Midlothian EH25 9RG,Scotland.
authors: A B
authors: AB
authors: Doeschl-Wilson
authors: 3Genus,PIC,Avda. Ragull 80,Sant Cugat del Valles,Barcelona 08173,Spain.
authors: C R G
authors: CR
authors: Lewis
authors: 1Animal and Veterinary Sciences Group,Scotland's Rural College,West Mains Road,Edinburgh EH9 3JG,Scotland.
authors: R
authors: R
authors: Roehe
mesh_terms: D000374:Aggression; D000818:Animals; D001947:Breeding; D005260:Female; D008297:Male; D012867:Skin / Q000293:injuries*; D034421:Sus scrofa / Q000235:genetics / Q000502:physiology*
keywords: aggression; genetics; pigs; selection; skin lesions