Associated Press
05-11-07
New study from Iowa State University rekindles debate over putting pregnant
sows in crates
By Amy Lorentzen
ASSOCIATED PRESS
AMES, Iowa – A new study is raising questions about the effectiveness of small,
metal crates for pregnant pigs that animal welfare groups say are cruel and
inhumane.
Researchers from Iowa State University found that allowing pregnant pigs to
move freely in group housing structures called hoop barns could be less costly
and just as productive as the narrow, individual crates.
“What we found was that there appears to be no real difference in pig
performance between the two,” said Peter Lammers, an ISU graduate
research assistant who conducted data analysis for the 21⁄2-year study.
There has been a backlash against placing pregnant sows in the gestation
crates. Some food processors and fast food chains have pledged not to purchase
meat from producers who use them, and some chefs said they would only use
crate-free pork. The European Union has decided to phase out the crates by
2013, while voters in Florida and Arizona have approved ballot initiatives to ban
them over the next few years.
“Highly intelligent animals, curious animals are crammed in a 2-foot-by-7-foot
cage that doesn't even allow them to turn around,” said Wayne Pacelle, CEO of
the Humane Society of the United States.
He said the sows remain in the cages for most of their four-month pregnancies,
amounting to about three years by the time they're eventually slaughtered.
The pork industry has defended the use of the gestation crates, which allow
producers to house as many pigs as possible in one building. Industry
representatives argue that pregnant sows can be aggressive toward one another
in groups, and that the stalls allow for equal feeding and care of each sow.
Individual management of the animals has been thought to aid their productivity.
Dave Warner, a spokesman for the Washington, D.C.-based National Pork
Producers Council, which lobbies for the nation's 67,000 pork producers, said the
majority of the group's members use gestation stalls, though he noted that both
the crates and group housing have their advantages and disadvantages.
The ISU study was conducted at a research farm in southwest Iowa. It compared
sows housed in stalls in mechanically ventilated confinement buildings to those in
naturally ventilated hoop barns with straw bedding.
Researchers who tracked 957 litters from 353 sows found that sows in the hoop
barns gave birth to more live pigs per litter than those confined in gestation stalls.
They also found that group housing may produce pigs at a lower cost – as much
as 11 percent less per weaned pig – than the gestation stalls, Lammers said.
He said sows in the hoop barns may have done better because of the bedding
and ability to huddle, which allows them more control over their temperature.
Individual feeding stalls in the hoop barns continued to allow for feed
management.
Even though soiled straw must be removed, the researchers said group housing
may not require more labor per animal than gestation stalls.
“In the United States, using a bedded system for gestating sows in hoop barns is
relatively unfamiliar,” Mark Honeyman, animal science professor and
coordinator of ISU's Research Farms, said in a statement. “With increased
experience, management will evolve and production may be enhanced.”
Lammers said the purpose of the study “wasn't to say one view was right, or one
view was wrong.”
“The purpose of this report was to examine what are the impacts of the types of
gestation sow housing,” he said.
A related study, based on a survey of general contractors and equipment and
materials suppliers, said the estimated construction cost per gestating sow in
hoop barns was $552, compared with $815 for the crates.