Aggressive and sexual behaviour of growing and finishing pigs reared in groups, without castration
Aggressive and sexual behaviour in entire males and females were studied on 408 pigs. The sum of aggressive interactions in the pen during routine feeding (ALP) was lowest in single-sex pens with females. ALP was higher at 132 than at 155 days. High ALP correlated with high average growth rate. Aggressive interactions in a competition test (IA) increased after slaughter of the three fastest-growing pigs in a pen (at 155 days), although the slaughtered pigs had initiated the most IA earlier (at 132 days). Entire male pigs displayed more sexual behaviour (mounting) than females. In 15% of entire males and 6% of females there were health problems specifically involving lameness or injured legs or feet. Five entire males and one female were euthanized in response to lameness or leg fracture. The rearing of entire male pigs may cause welfare problems, given their higher levels of aggression and sexual behaviour.
Document Type: Research Article
Affiliations: 1: Department of Animal Breeding and Genetics, Swedish Univeristy of Agricultural Sciences (SLU), Uppsala, Sweden 2: Food Science, SLU, Uppsala, Sweden 3: Animal Nutrition and Management, SLU, Uppsala, Sweden 4: Animal Environment and Health, SLU, Uppsala, Sweden 5: L'Institute National de la Recherche Agronomique (INRA), SystÃ¨mes d'Elevage Nutrition Animale et Humaine, Saint-Gilles, France
Publication date: 2006-11-01