When groups are formed in group housing of sows during gestation, some degree of aggression is present. This may affect farrowing weight and increases number of scratches, even though the aggression is usually short lived. Sows that were re-grouped within a few days of breeding had five experimental social treatments applied to reduce aggression levels. Out of the social treatments used, the one with the most potential was the Familiar treatment which involved using the same social group as the previous gestation reduced injuries and aggression. On the first day following regrouping, if dominant sows were present, aggression and injuries decreased. Protection did not have an effect on aggression or injuries.
Comparison of Management Factors Affecting Aggression in Group Housed Sows (full article)
