Do hoop structures offer an alternative to gestation stalls? Iowa State University researchers are studying the prospect and say the results are encouraging, in terms of sow performance and economics.

“We found reproductive performance can be maintained or enhanced in well-managed group-housing systems for gestating sows, such as deep-bedded hoop barns, without increasing labor,” says Mark Honeyman, coordinator of Iowa State’s research farms. “We found group housing may produce pigs at a lower cost than individual gestation stalls, and the pigs could qualify for niche markets.”

For 2.5 years, researchers tracked 957 litters from 353 sows to evaluate the effects of two gestation housing systems on sow and litter performance. One system involved individual gestation stalls in a mechanically ventilated confinement building with a partially slatted floor and a manure-flush system. The other involved group pens with individual feeding stalls in deep-bedded, naturally ventilated hoop barns.

The sows in the hoop barns farrowed more live pigs per litter than sows gestated in stalls. Peter Lammers, graduate research assistant, cites the bedding as one possible reason. “The ability to huddle together or maintain distance between animals may have allowed gestating sows in hoop barns more control over their thermal environment,” he says. “The hoop barns are a low-cost shelter, so we can allow each sow more space. Also, feeding stalls let us manage the grouped sows as individuals.

A related study compared the economics of the two sow-gestation systems. Researchers surveyed   Midwest agricultural contractors, as well as equipment and material suppliers. Those responses were used to develop cost estimates per sow space.

“Estimated construction cost per gestating sow space for group housing in hoop barns was $552, compared with $815 for individual sow stalls — a 32 percent reduction,” says Jay Harmon, professor of agricultural and biosystems engineering.

Operating costs are similar for both systems. “But total costs per weaned pig are less for the hoop system,” says James Kliebenstein, economics professor. “When the number of live pigs produced per sow was considered, the hoop, group-housed system had a weaned-pig cost that was 11 percent less than the individual-stall system.”

Honeyman says research shows that group systems may not require more labor per animal than individual gestation stalls, and in some cases may require less. “But the labor and skill sets needed may be different,” he notes. “Individual gestation stalls in are the result of decades of experience and refinement. In the United States, using a bedded system for gestating sows is relatively unfamiliar. With increased experience, management will evolve and production may be enhanced.”