Highly "efficient" conventional hog operations depend
on routine medications and mechanization to keep going. But
some Swedish farmers, who have refocused their operations in
the past five years around their hogs' quality of life, say
that by doing better by their animals, they're also doing better
in Swedish sow group systems commonly feature sophisticated
ventilation, deep-straw bedding, a raised piglet
creep area, and insulated but unheated barns. Tomas
and Magnus Carlevad designed this nursery for their
farm in southeastern Sweden.
These farmers are pioneers in adapting structures,
handling practices and management to let pigs really be pigs.
They are reducing their hogs' physical and psychological stress
to make them more productive. New farrowing and piglet-handling
techniques incorporating group nursing and deep-straw bedding
have been especially successful in weaning high numbers of
piglets per sow. These producers see humane treatment as an
opportunity for profitable innovation, not as a call to arms
to defend conventional practices.
"They're not just tinkering to make a conventional system
of crates a little better ," says Marlene Halverson,
a Ph.D. candidate in agricultural and applied economics at
the University of Minnesota. Halverson knows many innovative
Swedish hog farmers and specialists from her visits there.
"The idea is to figure out what hogs would do if they
were able to behave normally for their species, then approximate
the stimuli of a natural setting wherever possible,"
use about 2 tons of small-grain straw per sow per
year. The long-stemmed, loose straw satisfies foraging
instincts, keeps the herd warm and maintains good
health by keeping the animals dry.
Letting your hogs be your guide may seem like naive advice,
but Halverson says that this perspective can explain some
current dilemmas in conventional production. "There were
reasons producers went to routinely using antibiotics, docking
tails and crating sows as systems became more space- and capital-intensive,"
In recent decades, increasing the intensity of production
has led to more confined housing, crowding, temperature and
ventilation problems; more barren environments; and less attention
to how individuals were grouped and fed. Hogs have responded
to this stress with atypical behaviors such as tail- and vulva
biting and fighting. The high investment and operation costs
of restrictive housing has pushed farmers to seek greater
economy of scale by raising more pigs. Each step in this direction
has decreased their opportunity to use true husbandry and
increased dependence on technologies developed off the farm,
To reach a high level of welfare for animals, we first need
to know how they would be living if we weren't interfering
with them, Halverson explains. "This means understanding
how pigs as a species respond in general to their environment
and each other, and also how each sow responds to a particular
situation," she says.
The next steps are just as crucial. "To make this welfare
for livestock a practical reality, farmers need a working
knowledge of natural hog behaviors; profitable and aesthetically
pleasing systems that they will want to work in and invest
in; and solid markets that value the way hogs are raised."
Laws Spur Innovations
Two Swedish laws in the late '80s forced a change in how
all livestock are viewed there — not as just an agricultural
product, but as species with different needs and behaviors.
The first was put into force in 1986 at the request of farmers
who wanted to make their products more attractive to Swedish
consumers. The law banned subtherapeutic or prophylactic use
of antibiotics in animal feeds. Unexpectedly, however, the
law's effects caused profound changes in the nation's piglet
As was well-publicized in the U.S. farm media, one of the
immediate effects of the feed antibiotics ban for many Swedish
farmers was more scours at weaning, requiring more therapeutic
antibiotic use for the young pigs.
By contrast, some Swedish farms had no scours at weaning,
notes Bo Algers, a veterinary ethologist (specialist in animal
behavior) and a research manager at the Swedish University
of Agricultural Sciences. These farms had healthful production
environments that put less stress on pigs by keeping them
clean, using lower stock densities, and bedding with straw
to keep pigs warm and dry. This observation encouraged farmers
whose herds had problems with scours at weaning to change
the production environment for piglets rather than continue
to administer antibiotic treatments. That move paved the way
for designing freer systems of farrowing and lactation as
well, Halverson reports.
At the same time, Swedish hog farmers were looking for simpler,
lower-cost ways to produce high-quality pork. They wanted
a competitive edge in anticipation of the nation's entry into
the European Common Market. They started putting up multi-use
hog buildings designed with more unobstructed space that cut
costs by reducing labor, veterinary expenses and equipment
These farmers had a head start when a second law affecting
livestock production, Sweden's Farm Animal Protection Act,
broke new ground in '88. The law mandated housing systems
that provide a good environment for animals "so as to
promote their health and allow natural behavior." It
phased out farrowing crates and other restrictive facilities,
helping the producers identify the most important natural
hog characteristics were a number of researchers, including
Algers and another ethologist, Per Jensen.
freedom of movement and time to bond with their
litters show strong maternal instincts through weaning,
which is best done gradually to diminish stress
for sows and piglets. Farmer Gunnar Ljungstrom of
west-central Sweden incorporated these features
in the system he developed to allow natural hog
For three years starting in 1984, Jensen had studied the
daily activities of Swedish Landrace sows released into a
semi-natural setting. He doesn't suggest pigs need to be in
the wild to be raised humanely. But the outdoor setting provides
insight on the motivations behind sows' behaviors that scientists
or farmers could never have understood by watching sows in
"It's like a computer that has been given information
it can't use. Indoors, we see tightly confined animals behaving
in ways that are basically just error messages in response
to negative parts of their environment," says Jensen.
"Outside, I watched both pre-programmed and spontaneous
behaviors without disruptions from physical obstructions and
husbandry routines. These sows behaved just as wild ones do,
varying only in degree or intensity of a given action."
Jensen' s most important findings were in the areas of:
Feeding. In the natural setting, sows spent
up to 8 hours a day foraging, regardless of how much food
they were fed. The discovery showed the difference between
being nutritionally satisfied and behaviorally hungry, Jensen
says. Farmers can use ad lib feeders to accommodate this strong
food-search instinct. Some units require sows to manipulate
controls to get small amounts of feed, greatly prolonging
feeding time and sow satisfaction, says Jensen.
Grouping. In the semi-natural setting of
Jensen's experiment, the pigs formed social groups. This finding
influenced the production setting of new Swedish systems.
Now, even conventional hog producers there use straw bedding
and group rooms for pregnant sows, compared with the nearly
universal bare-floor management and gestation crates of 20
Keeping a set of sows moving through the production system
together eliminates the stress of mixing groups. Swedish farmers
have found various ways of successfully introducing new sows
and gilts to established groups. In one group-nursing system,
for example, groups are disrupted temporarily when sows are
put into individual pens for two weeks around farrowing. Farmers
say they can add a new sow with her litter smoothly during
the nursery phase, when the group re-forms as sows leave their
farrowing pens and are preoccupied with mothering.
Nesting. "The single, strongest instinct
for a sow is to nest the day before farrowing," says
Jensen. To do this she needs bedding materials and space.
Roomy rectangular pens that allow sows to freely turn around
to see their piglets have greatly decreased sow stress during
and just after farrowing, and have contributed to increased
piglet survival. Outdoor systems in the Midwest and South
show similar results.
Weaning. In the semi-wild environment of
Jensen' s experiment, sows finished weaning their piglets
in about 17 weeks, a period far longer than is feasible for
production. Jensen says a quicker, but still gradual, weaning
at five to six weeks seems to work for sows, piglets and producers
watching their bottom line. Sows given more time to lactate
in the new Swedish group systems often come back into heat
within a month of farrowing.
New Thoughts, Altered Barns
Since the late '80s, Swedish farmers have experimented with
behavior- appropriate designs by simplifying over-equipped
barns, using older wooden buildings and erecting new structures,
some complete with electronic ventilation sensors and observation
windows. Putting the natural-setting research findings into
practice has meant lots of trial and error, with results shared
freely between producers and their advisers. Discoveries at
the farm level include:
Breeding cycles and piglets require careful
attention when sows are kept in groups. Sows need to farrow
within a week of each other to keep their piglets within a
compatible age range. Penning sows ready to cycle next to
boars helps to synchronize estrus naturally. Providing "retreat
areas" in the sow gestation pens gives newly introduced
sows or gilts protection while they find their social niche
in the group. This decreases stress and increases breeding
All-in/all-out handling simplifies labor
and management: It gives farmers a good window to remove manure
and sanitize rooms between groups.
A quiet environment is critical for a sow
to communicate with her litter. Researchers found that sow
milk let-down lasts only 20 seconds, on average. Sows grunt
to signal a nursing opportunity is imminent. Piglets that
miss the call because there is too much mechanical noise or
they don't recognize their mother don't get their share of
milk and colostrum, and get off to a slow start.
Closed, insulated barns with deep straw packs
maximize piglet survival but require high-volume air movement.
The straw-manure mixture gives off heat and gases as it composts.
Simply installing bigger fans caused too much noise for piglet-sow
nursing communication. Farmers isolated fans and built quieter
Peaceable interactions take planning and
room. When a sow's "personal space" is free of perceived
challenges from other sows, she has less reason to fight to
defend her status. If housing allows sows to meet with at
least 6.5 feet between them, a lower-ranking sow can show
her submissiveness by turning her head to the side, avoiding
the "provocation" of a direct meeting that might
lead to a fight.
Creating and managing these environments demands a depth
of knowledge of hog tendencies and behaviors. The emphasis
in conventional systems on technology, volume and isolation
of individual sows provide younger farmers few chances to
learn about natural hog instincts, says Halverson. "Intensive
confinement systems that stifle an animal's natural behaviors
don't give the opportunity to know our animals well,"
she says. "We need to expand the human capital investment
in hog management to foster true husbandry as the main value
the farmer 'sells.'"
Sows given freedom of movement and time to bond with their
litters show strong maternal instincts through weaning, which
is best done gradually to diminish stress for sows and piglets.
Farmer Gunnar Ljungstrom of west-central Sweden incorporated
these features in the system he developed to allow natural
In these Swedish barns, farmers have to get in and walk among
their pigs at least once a day to develop mutual trust with
the animals. "Bo Algers recommends the farmer spend at
least 30 seconds each day with each sow housed with a group,"
says Halverson. "They expect the sows to run up and play,
to nip at their legs and run away." Piglets that are
lethargic or stay buried in the straw show they may be ailing
and need some attention.
Modern domestic sows are the product of 200 years of selective
breeding for external and physical characteristics. Yet even
after repeated farrowings in confinement, sows still show
the nest-building tendency just before giving birth. Pawing
the floor and bar-biting don't look like visible nesting actions,
but Per Jensen says the movements reflect what confined sows
do when they can't fulfill their instincts to isolate themselves,
locate a site and construct a nest.
"When we prevent a sow from nesting, we set up a stressful
situation,"says Halverson. "When we put her in a
crate with feed and water, we feel we've met all her needs
— from our point of view. We don't see why she needs
to move around to find food or to watch her piglets or to
respond to their distress calls."
But in a natural environment, as farmers with outdoor herds
know, adult pigs spend a great part of the day foraging and
exploring their environment. Nest building in the wild has
survival value. For such inbuilt motivations, the process
can be as important as the product. "By providing just
the ends, we do not satisfy a sow's need to go through the
means. A few minutes to gobble up concentrate doesn't satisfy
the urge to forage," says Halverson. "The more we
do for the sow in the crate, the less she can do for herself
and the more her insecurity, fear and stress levels rise."
About 40 percent of Swedish hog farmers now use behaviorally
sound systems of piglet production. These are based on barrier-free
farrowing pens,either conventional metal built-ins close to
a group grower room or sturdy plywood rectangles temporarily
set along the perimeter of the farrowing room itself. Pens
range in size from the legally required 5.5 square yards up
to a more sow-friendly 9 square yards.
Piglets stay in the pen for the first week to 10 days, long
enough to form strong bonds with their mother. Then the sows
rejoin the group with their litters. While group-management
systems have failed in some countries, Halverson says they
work well in Sweden because of:
Abundant use of clean straw — about
2 tons per sow per year. Whole, unopened bales help satisfy
the sows' and piglets' desire to forage and manipulate their
environment. Swedish farmers prefer large round bales, because
they give pigs the most physical challenge and because long
stems stay looser in the straw pack, allowing more aerobic
composting. Group-system buildings have doors large enough
for skid-steer loaders to remove the manure between groups.
An individual feeding station for each sow
in gestation rooms that protects individuals from the negative
aspects of group-feeding dynamics. By locking the stations
for half an hour at feeding, the farmer prevents dominant,
fast-eating sows from rousting lower-ranked sows from their
positions and eating their food.
Swedish hog farmers who have mastered behavior-based systems
report multiple rewards. The farmers are happier about the
day-to-day interaction with their animals. Their figures show
lower long-term investment in structures, veterinary expenses
and overall labor costs, with better sow reproductive health
and productivity. Inger Johansson and her husband Torgil read
about Jensen's and Algers' research and started a group-nursing
system in 1986. "We wish we had built this system 25
years ago," she says. "If we ever had to choose
between changing back to the old conventional production or
pack our bags, we would pack our bags first."
Farmers who thrive with these systems are those who appreciate
individual behaviors within the herd and who develop an eye
for recognizing illness, discontent, fear and agitation. This
takes daily, direct contact in the pen — a kind of management
that is impossible without a workable sow-to-farmer ratio.
Halverson says a number of forces are changing Sweden's livestock
system, not only animal-welfare advocates. The primary push
comes from hog farmers determined to find low-cost, productive
systems that deliver the high-quality meat Swedish consumers
demand. She's not surprised that these systems work for the
pigs, too. "I think that if we as a society make provisions
for animals to be animals well, we will find, as they have
in Sweden, that we have a better chance that farmers will
be able to be farmers well."