E (P ), but a clear difference was present between barren and
E (P ), but a clear distinction was present involving barren and enriched pens (tail damage score nursery barren ..; enriched ..; P \).Throughout the finishing phase (weeks) high IGEg pigs had a reduced tail harm score (high ..; low ..; P ), as well as the good impact of enrichment remained (imply tail harm score finishing barren ..; enriched ..; P \).This resulted in an additive effect of IGEg group and straw enrichment on tail harm, without the need of interactions in between these two components (P ).Consumption of Jute Sacks From week onward a jute sack was attached towards the wall of every pen to limit tail biting behaviour (Fig.).There was no interaction between IGEg group and housing condition for the consumption of jute sacks (P ).Discussion We have investigated the behavioural consequences of a single generation of divergent selection for IGEg in pigs in two housing systems.The divergent IGEg groups showed structural differences in biting behaviours directed towards pen mates and for the physical atmosphere through the finishing phase.This indicates that choice on IGEg may well alter a array of behaviours, and even behaviours not related to group members, like biting on objects in the atmosphere.This suggests that choice on IGEg will not merely alter social interactions, but rather results in changes in an internal state of the animal from which variations in behaviour may arise.Fig.Tail damage score for high IGEg pigs in barren pens, higher IGEg pigs in enriched pens, low IGEg pigs in barren pens, and low IGEg pigs in PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21310672 enriched pens.Note that the yaxis ranges from to .while tail damage scores from individual pigs may well range from top rated ).In pens with higher IGEg pigs these sacks had to be replaced significantly less frequently than in pens with low IGEg pigs.More than a Finafloxacin period of weeks, high IGEg pigs consumed ..jute sacks per pen, whereas low IGEg pigs consumed ..sacks per pen (P ).Pigs inBehav Genet Possible Underlying Mechanisms The origin of biting behaviour may be found in amongst others aggression, frustration, anxiety, or upkeep of dominance relationships (Scott ; Marler ; Schr erPetersen and Simonsen).Aggression and competition have already been connected with IGEs inside a wide array of taxa (reviewed by Wilson), for example in laying hens (Cheng and Muir), and had been also anticipated to underlie IGEg in pigs (Rodenburg et al).Pigs chosen for higher IGEg did show subtle differences in aggressive behaviour (Camerlink et al), but most biting behaviour was unrelated to aggression.The expression of aggressive and competitive behaviours might, even so, have already been tempered by ad libitum feeding (Camerlink et al).Pigs of high IGEg have been recommended to become superior in establishing dominance relationships (Rodenburg et al.; Canario et al.; Camerlink et al), but this doesn’t clarify the variations in biting on objects.The varying biting behaviours appear far more to originate from frustration or stress.Pigs have a sturdy intrinsic need to root and forage, and when this need can’t uncover an outlet within the physical environment it might be redirected to group members (e.g.Schr erPetersen and Simonsen).Tail biting, ear biting, and chewing on distraction material might therefore possess a comparable motivational background.These behaviours have also been associated to aggravation, tension, and fearfulness (Taylor et al.; Zupan et al).Further behavioural and physiological information recommend that high IGEg pigs could possibly be better capable of handling stressful situations and are much less fearful (Camerlink et al.; Reimert et al).Simi.