With the current social pressure being placed on gestation-sow housing, many producers are re-examining management skills required to facilitate group-pen gestation. 

The Ontario Ministry of Agriculture has listed several practices that have been shown to reduce aggressive behavior when sows are housed in group pens. The following suggestions vary by labor and cost requirements.

  • Wean sows into breeding crates. Crates prevent injuries associated with sow activities during estrous. Many producers hold sows in crates until 28 days after confirming pregnancy. Others have success when sows are mixed after seven days in the crates or immediately after breeding. Implantation typically occurs 12 to 14 days after breeding, so it may be best to group sows before or after this time.
  • Add extra feed to the pen floor before sows enter. This is a distraction device. Sows become engrossed in eating or exploring their environment and tend to fight less. It also helps if you feed up to 1.5 times the normal daily feed rations for the first two or three days after a group is mixed.
  • Add a boar to the pen. A boar may help minimize aggressive encounters between sows. Select the boar carefully, however, as it requires a boar of a stable temperament to perform this role.
  • Mixing times. Try mixing sows at the end of the day, then turn off the lights. When combined with extra feed, this also may reduce fighting.
  • Sort sows by size. The goal is to achieve a uniform body size. Size discrepancies can boost overly dominant or overly submissive behavior within a group.
  • Group size (20 or more). Large groups of sows often help reduce aggression. It is easier for individuals to hide in a large group, and it also limits the tendency for the sows to establish a hierarchy.
  • Use partition walls. Providing pen dividers gives sows a place to escape to when pursued and offers the animals some housing choices. 
  • Spread out the feed. By spreading the feed out over more of the floor surface, you can reduce aggressive encounters during feeding. The addition of an inverted Y or cone distribution to the feed drop can do this reasonably well.
  • Multiple feedings. Feeding once a day causes sows to hoard feed and increases fighting. Feeding three or more times a day creates calmer sows at feeding.
  • Suggested innovation. Use one well-laid-out mixing pen for the week after the sows leave the breeding crates. If at the end of this week the sows must be moved again, at least the worst fighting may be over.