Large Pens
Across the world and especially in the United States, the stall system dominates conventional pig barns. Sows are kept in 2x7 foot stalls that are just large enough for "sternal recumbency," which means lying on their bellies, feet tucked underneath. That means the pigs cannot turn around, just stand up to eat or lie down to sleep. Throughout their lives and production cycle, they are moved to various stalls, but they are all the same size.
In contrast, the dominant system in Europe is large pens, where groups of sows live together. The only time a sow is isolated is when she needs special care, like when she's ready to give birth or if she gets sick or injured.
There are a number of different Northern European pen designs, all of which function in slightly different ways. Truebridge cherry-picked the designs that best fit American barns and farmers. Free-access stalls for the breeding stage, large pens with nests for the gestation stage, and combi-pens for delivery and lactation.
The pen versus stall system has many animal welfare benefits. At the most basic level, it provides pigs with enough space to move around naturally, which gives them more control over making themselves feel comfortable and secure.
Moreover, an important part of pig life lies in its social structure. Large pens give pigs access to friends and collaborators. Pigs have a non-hierarchical status system, so although some sows tend to be dominant and other sows submissive, they don't establish and defend a ranked pecking order. That means they rarely quarrel as long as passageways are wide enough for a submissive pig to pass a dominant pig without provoking her.
It's been demonstrated that there is less fighting in larger pig herds. Large group sizes also make it easier for farmers to occasionally introduce a few new pigs, without disrupting the social scene too much. Much like a new kid joining a school classroom midway through the year.
So, just how much space is needed for a large communal pen? European barn designers have found that if a pen is too spread out, the pigs tend not to make it all the way to the bathroom in time, leading to dirtier sleeping areas. Just the way people claim favorite seats and hangout spots, pigs claim a location and return to it whenever they lie down. And Canadian swine behavioralist Harold Goynou, finds that when there are too few pigs in a pen, areas that would usually be claimed for sleeping spots swiftly become alternate bathrooms.
Truebridge pens are designed to be big enough to give the pigs plenty of room to wander and romp, but well-proportioned enough that the zones stay well-defined and the bedding snug and clean. Designing the right configuration of pen is not easy. You have to really know pigs well. |
