Better Pork - October 2016

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26 October 2016
Pork News & Views
abnormal (stereotypic) behaviour which is
an animal welfare concern. When sows are
housed in stalls, we often see this abnormal
behaviour expressed as bar-biting or sham-
chewing. In group housing systems, this may
be one reason why sows can become aggres-
sive toward other sows. Dietary fibre can help
increase the feeling of satiety, and reduce the
expression of abnormal behaviours in sows,
regardless of their housing system.
There are three aspects to consider with
fibre use: the amount of fiber, the physical
characteristic of the fibre, and the type of
fibre. In the European Union, diets often
contain 9-12% crude fibre, but may be as high
as 20% without affecting animal performance.
Having a higher crude fibre content is helpful,
but more important than the total fibre con-
centration is the physical size of the fibre and
the balance between fermentable fibre and
crude fibre. With physical size, more coarse
materials provide better gut fill for the sow,
and thus are better at reducing hunger than
a finely ground fibre source. Some potential
strategies for feeding coarse fibrous materi-
als would be to provide hay or straw in racks
(Figure 4), as cubes or as bedding.
The value of providing fermentable fibre
sources to sows has been shown in many re-
search studies. Ingredients such as sugar beet
pulp, alfalfa meal and soybean hulls contain
60-70% non-starch polysaccharides, which
can be fermented by bacteria in the intestinal
tract. This fermentation occurs over an ex-
tended period of time, and helps to provide a
more stable release of energy to the sow, thus
helping her feel full for longer periods. Ingre-
dients such as sugar beet pulp are becoming
more common in sow diets, and have been
shown in many research studies to decrease
abnormal behaviours in sows without having
negative impacts on performance.
Remember, we no longer are feeding sows
just for optimal performance; we are also
feeding to improve animal welfare. Keep in
mind that the nutritional requirements of
sows change with size, parity and stage of
gestation. Consider using phase or precision
feeding techniques to meet her requirements
more closely. Remember that each sow and
each housing system is different. Monitor
body condition scores on a regular basis and
adjust each sows feed allowance in order
to maximize her productivity. Design your
group housing system to reduce feeding
related aggression as much as possible, and
include fermentable and coarse fibre in the
diet to help increase her feeling of fullness
throughout the day.
Laura Eastwood, Swine Specialist
519-271-6280
Addressing Some Myths Around
Group Sow Housing
At the Group Sow Housing Seminar in Sep-
tember, Dr. Jennifer Brown from the Prairie
Swine Seminar discussed some possible
misconceptions. As usual, there is little black
and white and it is important to understand
the details of any study or report that appears
to provide a single answer.
The ‘Myths’ she tackled were: Aggression is a
major problem in groups (because sows are
naturally aggressive); Group housing is more
expensive; Sows in groups are less productive;
All group gestation systems are alike; Mixing
before 4 weeks gestation reduces conception
rate and litter size; Group housing will be
mandatory by 2024.
This article attempts to summarize Dr.
Brown’s assessment of these often complex
issues.
1. Aggression is a major problem because
sows are naturally aggressive
There are a number of factors influencing
aggression: Individual differences (genetic
variation); Socialization (development and
experience); and Group Size.
Sows can be socialized and conditioned
through experience to tolerate other sows
in order to reduce aggressive behaviour fol-
lowing mixing. Research shows that piglets
socialized with other litters by 12 days of
age gain critical ‘social skills’ and improved
tolerance of other animals later in life.
Multiple movements and mixing events
improve sows’ social adaptability. When
mixed with strangers, market hogs kept
in smaller groups are quicker to fight and
spend more time fighting than pigs kept in
large groups (groups of 18 vs 108 animals),
so larger sow groups may reduce problems
with aggression. Genetic selection for
lower aggression and passive temperament,
which may have been neglected in recent
years, has potential.
2. Group housing is more expensive
There are few well-documented reports to
support or refute this. A 2012 report from
Quebec’s CDPQ estimates that new builds
for groups can be cheaper than stalls, be-
cause there is less penning required. With
renovations, it is difficult to assess because
the condition of the original structure
has a huge impact on cost depending on
whether it needs repairs or upgrading dur-
ing the renovation. A key factor that can’t
be ignored is the efficiency of the barn de-
sign and management after the conversion,
aside from the actual costs of conversion.
3. Sows in groups are less productive
There are a number of studies and scien-
tific reviews that show similar production
levels in stalls and groups. Differences
in productivity could be a result of many
factors, but there is no consistent evidence
of a difference between housing systems.
During the transition, of course, produc-
tion will probably be negatively affected
by sow movement, increased culling, etc.
Producers have reported that following the
transition period production will return to
normal or even improve. In the long term
production is determined by system design
and management. Sows in group housing
do not require more energy than those in
stalls, and benefit from improved thermo-
regulation since they can avoid draughts
and choose where to sleep. The benefits of
greater activity appear to include increased
Figure 4. Straw provided in racks as a source
of fibre and enrichment