This Primefact provides pig owners with general
guidelines to consider when designing and
managing pregnant sows in groups.
What are the options?
The options for housing pregnant sows in groups
revolve around the type of feeding system used.
The most common systems are:
• Floor feeding
• Liquid trough feeding
• Electronic feeding stations (EFS)
• Free access feeding stalls
The suitability of each system within an existing
farm will depend on cost (capital and operating),
productivity of the system (pigs born/sow/year,
culling rates), the producer’s ability to manage the
new system and building compatibility with existing
housing.
The aims of any group housing system are to
control the feed intake of individual sows, provide
low levels of aggression during feeding and reduce
aggression around re-grouping of sows.
What things affect these
outcomes?
There are advantages and disadvantages of all
systems. The success of each will depend on:
• Quality of husbandry – skilled and motivated
stockpersons are key for early detection and
appropriate treatment of sows that are sick or
injured.
• Space allowance. The Model Code of Practice
for the Welfare of Animals (Pigs) states that
each sow must have at least 1.4 m2 of floor
space if housed in groups. The optimal space
allowance to reduce the risks of injuries, skin
abrasions and vulva bites has not been
determined, but there should be adequate
space for sows to access feed and water
without competition, to rest in a clean, dry area
as a group and a separate area for dunging.
• Quality of space. Areas where sows may
commingle should be at least 3 m wide, to
allow sows to pass each other.

• Pen divides. Solid pen divides encourage sows
to lie against them. An enclosed solid area with
enough space for each sow to lie separated
from a slatted dunging area is ideal.
• Group size. Having too many sows for each
feeding station does not allow all sows enough
time to access their daily feed ration.
Recommendations are:
- Gilts: maximum of 30 per station; Sows:
maximum of 50 sows where there is only 1
feeder in the pen; Sows: maximum of 65
where there is more than 1 feeder in the
pen.
- Use of bedding. Studies conducted in
Europe suggest that adding straw (approx.
200 g/sow/day) reduces culling rates in sows
housed in EFS systems compared to nostraw
housing. Bedding is likely to be more
advantageous in cold conditions than when
it is warm.
- Mixing unfamiliar sows. It is best to keep
sows in stable groups. If sows must be
mixed, do it after 4 weeks gestation (after
implantation of embryos) to minimize risks of
pregnancy loss.
- Allow an extra 5% of total gestation space to
house sick or compromised sows. Ensure in
hospital pens that about 2/3 of the flooring
has a solid, soft cover. Sows with foot and/or
leg problems will benefit from being placed
in recovery pens with dirt/compacted clay
flooring.
The advantages and disadvantages of each of the
main group housing systems are summarized
below.
Floor feeding
Advantages
• Lowest capital cost (requires only pen/yard
with solid flooring area).
• Simple, low maintenance.
• Allows simultaneous feeding of all sows.